Merge branch 'ami-cache-weights-addressing' into 'develop'

Draft: AMI - added caching of weights and addressing

See merge request Development/openfoam!744

src/TurbulenceModels/turbulenceModels/LES/LESdeltas/smoothDelta/smoothDelta.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2020 OpenCFD Ltd.
+    Copyright (C) 2016-2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -189,6 +189,23 @@ public:
                 template<class TrackingData>
                 inline bool equal(const deltaData&, TrackingData& td) const;
 
+                //- Interpolate between two values (lerp). Returns true if
+                //- causes changes. Not sure if needs to be specialised between
+                //- face and cell and what index is needed...
+                template<class TrackingData>
+                inline bool interpolate
+                (
+                    const polyMesh&,
+                    const point& pt,
+                    const label i0,
+                    const deltaData& f0,
+                    const label i1,
+                    const deltaData& f1,
+                    const scalar weight,
+                    const scalar tol,
+                    TrackingData& td
+                );
+
 
         // Member Operators
 
@@ -296,6 +313,17 @@ public:
 template<>
 struct is_contiguous<LESModels::smoothDelta::deltaData> : std::true_type {};
 
+//- Interpolation - used in e.g. cyclicAMI interpolation
+inline LESModels::smoothDelta::deltaData lerp
+(
+    const LESModels::smoothDelta::deltaData& a,
+    const LESModels::smoothDelta::deltaData& b,
+    const scalar t
+)
+{
+    return LESModels::smoothDelta::deltaData(lerp(a.delta(), b.delta(), t));
+}
+
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 

src/TurbulenceModels/turbulenceModels/LES/LESdeltas/smoothDelta/smoothDeltaDeltaDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
-    Copyright (C) 2019 OpenCFD Ltd.
+    Copyright (C) 2019,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -191,6 +191,40 @@ inline bool Foam::LESModels::smoothDelta::deltaData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::LESModels::smoothDelta::deltaData::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const deltaData& f0,
+    const label i1,
+    const deltaData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td) && f1.valid(td))
+    {
+        const deltaData w2(lerp(f0.delta(), f1.delta(), weight));
+        return update(w2, 1.0, tol, td);
+    }
+    else if (f0.valid(td))
+    {
+        return update(f0, 1.0, tol, td);
+    }
+    else if (f1.valid(td))
+    {
+        return update(f1, 1.0, tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::LESModels::smoothDelta::deltaData::operator==

src/dynamicMesh/meshCut/directions/directionInfo/directionInfo.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -242,6 +242,23 @@ public:
             template<class TrackingData>
             inline bool equal(const directionInfo&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const directionInfo& f0,
+                const label i1,
+                const directionInfo& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/dynamicMesh/meshCut/directions/directionInfo/directionInfoI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -287,6 +287,35 @@ inline bool Foam::directionInfo::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::directionInfo::interpolate
+(
+    const polyMesh& mesh,
+    const point& pt,
+    const label i0,
+    const directionInfo& f0,
+    const label i1,
+    const directionInfo& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return updateFace(mesh, -1, f0, tol, td);
+    }
+    if (f1.valid(td))
+    {
+        return updateFace(mesh, -1, f1, tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::directionInfo::operator==

src/dynamicMesh/meshCut/wallLayerCells/wallNormalInfo/wallNormalInfo.H

@@ -186,6 +186,23 @@ public:
                 TrackingData& td
             );
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const wallNormalInfo& f0,
+                const label i1,
+                const wallNormalInfo& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
             //- Test for equality, with TrackingData
             template<class TrackingData>
             inline bool equal(const wallNormalInfo&, TrackingData& td) const;

src/dynamicMesh/meshCut/wallLayerCells/wallNormalInfo/wallNormalInfoI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -191,6 +191,35 @@ inline bool Foam::wallNormalInfo::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::wallNormalInfo::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const wallNormalInfo& f0,
+    const label i1,
+    const wallNormalInfo& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return update(f0, td);
+    }
+    if (f1.valid(td))
+    {
+        return update(f1, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::wallNormalInfo::operator==

src/dynamicMesh/polyTopoChange/polyTopoChange/refinementData.H

@@ -197,6 +197,23 @@ public:
             template<class TrackingData>
             inline bool equal(const refinementData&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const refinementData& f0,
+                const label i1,
+                const refinementData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/dynamicMesh/polyTopoChange/polyTopoChange/refinementDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -248,6 +248,35 @@ inline bool Foam::refinementData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::refinementData::interpolate
+(
+    const polyMesh& mesh,
+    const point& pt,
+    const label i0,
+    const refinementData& f0,
+    const label i1,
+    const refinementData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return updateFace(mesh, -1, f0, tol, td);
+    }
+    if (f1.valid(td))
+    {
+        return updateFace(mesh, -1, f1, tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::refinementData::operator==

src/dynamicMesh/polyTopoChange/polyTopoChange/refinementDistanceData.H

@@ -229,6 +229,23 @@ public:
             inline bool equal(const refinementDistanceData&, TrackingData&)
             const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const refinementDistanceData& f0,
+                const label i1,
+                const refinementDistanceData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/dynamicMesh/polyTopoChange/polyTopoChange/refinementDistanceDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -278,6 +278,35 @@ inline bool Foam::refinementDistanceData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::refinementDistanceData::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const refinementDistanceData& f0,
+    const label i1,
+    const refinementDistanceData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return update(pt, f0, tol, td);
+    }
+    if (f1.valid(td))
+    {
+        return update(pt, f1, tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::refinementDistanceData::operator==

src/finiteVolume/fields/fvPatchFields/constraint/cyclicACMI/cyclicACMIFvPatchField.C

@@ -227,9 +227,15 @@ bool Foam::cyclicACMIFvPatchField<Type>::all_ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
         ++done;
     }
 
@@ -240,9 +246,15 @@ bool Foam::cyclicACMIFvPatchField<Type>::all_ready() const
             sendRequests_.start(),
             sendRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            sendRequests1_.start(),
+            sendRequests1_.size()
+        )
     )
     {
         sendRequests_.clear();
+        sendRequests1_.clear();
         ++done;
     }
 
@@ -260,9 +272,15 @@ bool Foam::cyclicACMIFvPatchField<Type>::ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if
         (
@@ -271,9 +289,15 @@ bool Foam::cyclicACMIFvPatchField<Type>::ready() const
                 sendRequests_.start(),
                 sendRequests_.size()
             )
+         && UPstream::finishedRequests
+            (
+                sendRequests1_.start(),
+                sendRequests1_.size()
+            )
         )
         {
             sendRequests_.clear();
+            sendRequests1_.clear();
         }
 
         return true;
@@ -483,7 +507,7 @@ void Foam::cyclicACMIFvPatchField<Type>::initEvaluate
         const Field<Type> pnf(this->primitiveField(), nbrFaceCells);
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -494,14 +518,20 @@ void Foam::cyclicACMIFvPatchField<Type>::initEvaluate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cyclicACMIPatch_.initInterpolate
         (
             pnf,
             sendRequests_,
-            sendBufs_,
             recvRequests_,
-            recvBufs_
+            sendBufs_,
+            recvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            sendBufs1_,
+            recvBufs1_
         );
     }
 }
@@ -547,12 +577,15 @@ void Foam::cyclicACMIFvPatchField<Type>::evaluate
             (
                 Field<Type>::null(),    // Not used for distributed
                 recvRequests_,
-                recvBufs_
+                recvBufs_,
+                recvRequests1_,
+                recvBufs1_
             ).ptr()
         );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if (doTransform())
         {
@@ -608,7 +641,7 @@ void Foam::cyclicACMIFvPatchField<Type>::initInterfaceMatrixUpdate
         transformCoupleField(pnf, cmpt);
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -619,14 +652,20 @@ void Foam::cyclicACMIFvPatchField<Type>::initInterfaceMatrixUpdate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cyclicACMIPatch_.initInterpolate
         (
             pnf,
             sendRequests_,
-            scalarSendBufs_,
             recvRequests_,
-            scalarRecvBufs_
+            scalarSendBufs_,
+            scalarRecvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            scalarSendBufs1_,
+            scalarRecvBufs1_
         );
     }
 
@@ -681,11 +720,14 @@ void Foam::cyclicACMIFvPatchField<Type>::updateInterfaceMatrix
             (
                 solveScalarField::null(),    // Not used for distributed
                 recvRequests_,
-                scalarRecvBufs_
+                scalarRecvBufs_,
+                recvRequests1_,
+                scalarRecvBufs1_
             );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
     }
     else
     {
@@ -738,7 +780,7 @@ void Foam::cyclicACMIFvPatchField<Type>::initInterfaceMatrixUpdate
         transformCoupleField(pnf);
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -749,14 +791,20 @@ void Foam::cyclicACMIFvPatchField<Type>::initInterfaceMatrixUpdate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cyclicACMIPatch_.initInterpolate
         (
             pnf,
             sendRequests_,
-            sendBufs_,
             recvRequests_,
-            recvBufs_
+            sendBufs_,
+            recvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            sendBufs1_,
+            recvBufs1_
         );
     }
 
@@ -798,11 +846,14 @@ void Foam::cyclicACMIFvPatchField<Type>::updateInterfaceMatrix
             (
                 Field<Type>::null(),    // Not used for distributed
                 recvRequests_,
-                recvBufs_
+                recvBufs_,
+                recvRequests1_,
+                recvBufs1_
             );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
     }
     else
     {

src/finiteVolume/fields/fvPatchFields/constraint/cyclicACMI/cyclicACMIFvPatchField.H

@@ -102,6 +102,28 @@ class cyclicACMIFvPatchField
             //- Scalar receive buffers
             mutable PtrList<List<solveScalar>> scalarRecvBufs_;
 
+
+            // Only used for AMI caching
+
+                //- Current range of send requests (non-blocking)
+                mutable labelRange sendRequests1_;
+
+                //- Current range of recv requests (non-blocking)
+                mutable labelRange recvRequests1_;
+
+                //- Send buffers
+                mutable PtrList<List<Type>> sendBufs1_;
+
+                //- Receive buffers_
+                mutable PtrList<List<Type>> recvBufs1_;
+
+                //- Scalar send buffers
+                mutable PtrList<List<solveScalar>> scalarSendBufs1_;
+
+                //- Scalar receive buffers
+                mutable PtrList<List<solveScalar>> scalarRecvBufs1_;
+
+
             //- Neighbour coupled internal cell data
             mutable autoPtr<Field<Type>> patchNeighbourFieldPtr_;
 

src/finiteVolume/fields/fvPatchFields/constraint/cyclicAMI/cyclicAMIFvPatchField.C

@@ -207,9 +207,15 @@ bool Foam::cyclicAMIFvPatchField<Type>::all_ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+    &&  UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
         ++done;
     }
 
@@ -220,9 +226,15 @@ bool Foam::cyclicAMIFvPatchField<Type>::all_ready() const
             sendRequests_.start(),
             sendRequests_.size()
         )
+    &&  UPstream::finishedRequests
+        (
+            sendRequests1_.start(),
+            sendRequests1_.size()
+        )
     )
     {
         sendRequests_.clear();
+        sendRequests1_.clear();
         ++done;
     }
 
@@ -240,9 +252,15 @@ bool Foam::cyclicAMIFvPatchField<Type>::ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if
         (
@@ -251,9 +269,15 @@ bool Foam::cyclicAMIFvPatchField<Type>::ready() const
                 sendRequests_.start(),
                 sendRequests_.size()
             )
+         && UPstream::finishedRequests
+            (
+                sendRequests1_.start(),
+                sendRequests1_.size()
+            )
         )
         {
             sendRequests_.clear();
+            sendRequests1_.clear();
         }
 
         return true;
@@ -319,9 +343,18 @@ Foam::cyclicAMIFvPatchField<Type>::getNeighbourField
 
 
 template<class Type>
-bool Foam::cyclicAMIFvPatchField<Type>::cacheNeighbourField()
+bool Foam::cyclicAMIFvPatchField<Type>::cacheNeighbourField() const
 {
+    // const auto& AMI = this->ownerAMI();
+
+    // if (AMI.cacheActive())
+    // {
+    //     return false;
+    // }
+    // else
+    {
         return (FieldBase::localBoundaryConsistency() != 0);
+    }
 }
 
 
@@ -350,11 +383,12 @@ Foam::cyclicAMIFvPatchField<Type>::getPatchNeighbourField
         }
 
         const auto& fvp = this->patch();
+        const auto& mesh = fvp.boundaryMesh().mesh();
 
         if
         (
             patchNeighbourFieldPtr_
-        && !fvp.boundaryMesh().mesh().upToDatePoints(this->internalField())
+        && !mesh.upToDatePoints(this->internalField())
         )
         {
             //DebugPout
@@ -418,7 +452,8 @@ template<class Type>
 Foam::tmp<Foam::Field<Type>>
 Foam::cyclicAMIFvPatchField<Type>::patchNeighbourField() const
 {
-    return this->getPatchNeighbourField(true);  // checkCommunicator = true
+    // checkCommunicator = true
+    return this->getPatchNeighbourField(true);
 }
 
 
@@ -491,7 +526,7 @@ void Foam::cyclicAMIFvPatchField<Type>::initEvaluate
         const cyclicAMIPolyPatch& cpp = cyclicAMIPatch_.cyclicAMIPatch();
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -502,14 +537,20 @@ void Foam::cyclicAMIFvPatchField<Type>::initEvaluate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cpp.initInterpolate
         (
             pnf,
             sendRequests_,
-            sendBufs_,
             recvRequests_,
-            recvBufs_
+            sendBufs_,
+            recvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            sendBufs1_,
+            recvBufs1_
         );
     }
 }
@@ -562,12 +603,15 @@ void Foam::cyclicAMIFvPatchField<Type>::evaluate
                 Field<Type>::null(),    // Not used for distributed
                 recvRequests_,
                 recvBufs_,
+                recvRequests1_,
+                recvBufs1_,
                 defaultValues
             ).ptr()
         );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if (doTransform())
         {
@@ -618,7 +662,7 @@ void Foam::cyclicAMIFvPatchField<Type>::initInterfaceMatrixUpdate
         const cyclicAMIPolyPatch& cpp = cyclicAMIPatch_.cyclicAMIPatch();
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -629,14 +673,20 @@ void Foam::cyclicAMIFvPatchField<Type>::initInterfaceMatrixUpdate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cpp.initInterpolate
         (
             pnf,
             sendRequests_,
-            scalarSendBufs_,
             recvRequests_,
-            scalarRecvBufs_
+            scalarSendBufs_,
+            scalarRecvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            scalarSendBufs1_,
+            scalarRecvBufs1_
         );
     }
 
@@ -691,11 +741,14 @@ void Foam::cyclicAMIFvPatchField<Type>::updateInterfaceMatrix
                 solveScalarField::null(),   // Not used for distributed
                 recvRequests_,
                 scalarRecvBufs_,
+                recvRequests1_,
+                scalarRecvBufs1_,
                 defaultValues
             );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
     }
     else
     {
@@ -757,7 +810,7 @@ void Foam::cyclicAMIFvPatchField<Type>::initInterfaceMatrixUpdate
         const cyclicAMIPolyPatch& cpp = cyclicAMIPatch_.cyclicAMIPatch();
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -768,14 +821,20 @@ void Foam::cyclicAMIFvPatchField<Type>::initInterfaceMatrixUpdate
 
         // Assume that sends are also OK
         sendRequests_.clear();
+        sendRequests1_.clear();
 
         cpp.initInterpolate
         (
             pnf,
             sendRequests_,
-            sendBufs_,
             recvRequests_,
-            recvBufs_
+            sendBufs_,
+            recvBufs_,
+
+            sendRequests1_,
+            recvRequests1_,
+            sendBufs1_,
+            recvBufs1_
         );
     }
 
@@ -829,11 +888,14 @@ void Foam::cyclicAMIFvPatchField<Type>::updateInterfaceMatrix
                 Field<Type>::null(),  // Not used for distributed
                 recvRequests_,
                 recvBufs_,
+                recvRequests1_,
+                recvBufs1_,
                 defaultValues
             );
 
         // Receive requests all handled by last function call
         recvRequests_.clear();
+        recvRequests1_.clear();
     }
     else
     {
@@ -918,7 +980,7 @@ void Foam::cyclicAMIFvPatchField<Type>::manipulateMatrix
         }
 
         // Set internalCoeffs and boundaryCoeffs in the assembly matrix
-        // on clyclicAMI patches to be used in the individual matrix by
+        // on cyclicAMI patches to be used in the individual matrix by
         // matrix.flux()
         if (matrix.psi(mat).mesh().fluxRequired(this->internalField().name()))
         {

src/finiteVolume/fields/fvPatchFields/constraint/cyclicAMI/cyclicAMIFvPatchField.H

@@ -113,6 +113,28 @@ class cyclicAMIFvPatchField
             //- Scalar receive buffers
             mutable PtrList<List<solveScalar>> scalarRecvBufs_;
 
+
+            // Only used for AMI caching
+
+                //- Current range of send requests (non-blocking)
+                mutable labelRange sendRequests1_;
+
+                //- Current range of recv requests (non-blocking)
+                mutable labelRange recvRequests1_;
+
+                //- Send buffers
+                mutable PtrList<List<Type>> sendBufs1_;
+
+                //- Receive buffers_
+                mutable PtrList<List<Type>> recvBufs1_;
+
+                //- Scalar send buffers
+                mutable PtrList<List<solveScalar>> scalarSendBufs1_;
+
+                //- Scalar receive buffers
+                mutable PtrList<List<solveScalar>> scalarRecvBufs1_;
+
+
             //- Neighbour coupled internal cell data
             mutable autoPtr<Field<Type>> patchNeighbourFieldPtr_;
 
@@ -134,7 +156,7 @@ class cyclicAMIFvPatchField
         virtual bool all_ready() const;
 
         //- Use neighbour field caching
-        static bool cacheNeighbourField();
+        bool cacheNeighbourField() const;
 
         //- Return neighbour coupled internal cell data
         tmp<Field<Type>> getNeighbourField(const UList<Type>&) const;

src/finiteVolume/finiteVolume/fvc/fvcSmooth/smoothData.H

@@ -209,6 +209,23 @@ public:
             template<class TrackingData>
             inline bool equal(const smoothData&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const smoothData& f0,
+                const label i1,
+                const smoothData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/finiteVolume/finiteVolume/fvc/fvcSmooth/smoothDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2013 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -191,6 +191,45 @@ inline bool Foam::smoothData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::smoothData::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const smoothData& f0,
+    const label i1,
+    const smoothData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    // TBD. What to interpolate? Do we have a position? cell/face centre?
+
+    if (!valid(td))
+    {
+        if (f0.valid(td))
+        {
+            operator=(f0);
+        }
+        else
+        {
+            operator=(f1);
+        }
+    }
+    else if (f0.valid(td))
+    {
+        operator=(f0);
+    }
+    else
+    {
+        operator=(f1);
+    }
+    return true;
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::smoothData::operator==

src/finiteVolume/finiteVolume/fvc/fvcSmooth/sweepData.H

@@ -207,6 +207,23 @@ public:
             template<class TrackingData>
             inline bool equal(const sweepData&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const sweepData& f0,
+                const label i1,
+                const sweepData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/finiteVolume/finiteVolume/fvc/fvcSmooth/sweepDataI.H

@@ -210,6 +210,45 @@ inline bool Foam::sweepData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::sweepData::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const sweepData& f0,
+    const label i1,
+    const sweepData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    // TBD. What to interpolate? Do we have a position? cell/face centre?
+
+    if (!valid(td))
+    {
+        if (f0.valid(td))
+        {
+            operator=(f0);
+        }
+        else
+        {
+            operator=(f1);
+        }
+    }
+    else if (f0.valid(td))
+    {
+        operator=(f0);
+    }
+    else
+    {
+        operator=(f1);
+    }
+    return true;
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::sweepData::operator==

src/finiteVolume/fvMesh/fvPatches/constraint/cyclicACMI/cyclicACMIFvPatch.H

@@ -220,9 +220,14 @@ public:
                 (
                     const Field<Type>& fld,
                     labelRange& sendRequests,
-                    PtrList<List<Type>>& sendBuffers,
                     labelRange& recvRequests,
-                    PtrList<List<Type>>& recvBuffers
+                    PtrList<List<Type>>& sendBuffers,
+                    PtrList<List<Type>>& recvBuffers,
+
+                    labelRange& sendRequests1,
+                    labelRange& recvRequests1,
+                    PtrList<List<Type>>& sendBuffers1,
+                    PtrList<List<Type>>& recvBuffers1
                 ) const
                 {
                     // Make sure areas are up-to-date
@@ -232,9 +237,14 @@ public:
                     (
                         fld,
                         sendRequests,
-                        sendBuffers,
                         recvRequests,
-                        recvBuffers
+                        sendBuffers,
+                        recvBuffers,
+
+                        sendRequests1,
+                        recvRequests1,
+                        sendBuffers1,
+                        recvBuffers1
                     );
                 }
 
@@ -243,7 +253,9 @@ public:
                 (
                     const Field<Type>& localFld,
                     const labelRange& requests,  // The receive requests
-                    const PtrList<List<Type>>& recvBuffers
+                    const PtrList<List<Type>>& recvBuffers,
+                    const labelRange& requests1,  // The receive requests
+                    const PtrList<List<Type>>& recvBuffers1
                 ) const
                 {
                     return cyclicACMIPolyPatch_.interpolate
@@ -251,6 +263,8 @@ public:
                         localFld,
                         requests,
                         recvBuffers,
+                        requests1,
+                        recvBuffers1,
                         UList<Type>()
                     );
                 }

src/mesh/snappyHexMesh/meshRefinement/wallPoints.H

@@ -251,6 +251,23 @@ public:
             template<class TrackingData>
             inline bool equal(const wallPoints&, TrackingData&) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const wallPoints& f0,
+                const label i1,
+                const wallPoints& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/mesh/snappyHexMesh/meshRefinement/wallPointsI.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2018-2023 OpenCFD Ltd.
+    Copyright (C) 2018-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -443,6 +443,41 @@ inline bool Foam::wallPoints::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::wallPoints::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const wallPoints& f0,
+    const label i1,
+    const wallPoints& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (valid(td))
+    {
+        return false;
+    }
+    else if (f0.valid(td))
+    {
+        operator=(f0);
+        return true;
+    }
+    else if (f1.valid(td))
+    {
+        operator=(f1);
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::wallPoints::operator==

src/meshTools/AMIInterpolation/AMIInterpolation/AMICache.C

@@ -0,0 +1,651 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "AMICache.H"
+#include "AMIInterpolation.H"
+#include "mathematicalConstants.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+Foam::scalar Foam::AMICache::cacheThetaTolerance_ = 1e-8;
+
+int Foam::AMICache::debug = 0;
+
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+Foam::scalar Foam::AMICache::getRotationAngle(const point& globalPoint) const
+{
+    if (!coordSysPtr_)
+    {
+        FatalErrorInFunction
+            << "No co-ordinate system available for theta evaluation"
+            << abort(FatalError);
+    }
+
+
+    scalar theta = coordSysPtr_->localPosition(globalPoint).y();
+
+    // Ensure 0 < theta < 2pi
+    if (mag(theta) < cacheThetaTolerance_)
+    {
+        theta = 0;
+    }
+    else if (theta < 0)
+    {
+        theta += constant::mathematical::twoPi;
+    }
+
+    return theta;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::AMICache::AMICache(const dictionary& dict, const bool toSource)
+:
+    size_(dict.getOrDefault<label>("cacheSize", 0)),
+    rotationAxis_(dict.getOrDefault<vector>("rotationAxis", Zero)),
+    rotationCentre_(dict.getOrDefault<point>("rotationCentre", Zero)),
+    maxThetaDeg_(dict.getOrDefault<scalar>("maxThetaDeg", 5)),
+    complete_(false),
+    index0_(-1),
+    index1_(-1),
+    interpWeight_(0),
+    coordSysPtr_(nullptr),
+    theta_(),
+    cachedSrcAddress_(),
+    cachedSrcWeights_(),
+    cachedSrcWeightsSum_(),
+    cachedSrcMapPtr_(),
+    cachedTgtAddress_(),
+    cachedTgtWeights_(),
+    cachedTgtWeightsSum_(),
+    cachedTgtMapPtr_(),
+    toSource_(toSource)
+{
+    if (size_ != 0)
+    {
+        theta_.resize(size_, GREAT);
+        cachedSrcAddress_.resize(size_);
+        cachedSrcWeights_.resize(size_);
+        cachedSrcWeightsSum_.resize(size_);
+        cachedSrcMapPtr_.resize(size_);
+        cachedTgtAddress_.resize(size_);
+        cachedTgtWeights_.resize(size_);
+        cachedTgtWeightsSum_.resize(size_);
+        cachedTgtMapPtr_.resize(size_);
+    }
+}
+
+
+Foam::AMICache::AMICache(const bool toSource)
+:
+    size_(0),
+    rotationAxis_(Zero),
+    rotationCentre_(Zero),
+    complete_(false),
+    index0_(-1),
+    index1_(-1),
+    interpWeight_(0),
+    coordSysPtr_(nullptr),
+    theta_(),
+    cachedSrcAddress_(),
+    cachedSrcWeights_(),
+    cachedSrcWeightsSum_(),
+    cachedSrcMapPtr_(),
+    cachedTgtAddress_(),
+    cachedTgtWeights_(),
+    cachedTgtWeightsSum_(),
+    cachedTgtMapPtr_(),
+    toSource_(toSource)
+{}
+
+
+Foam::AMICache::AMICache(const AMICache& cache)
+:
+    size_(cache.size_),
+    rotationAxis_(cache.rotationAxis_),
+    rotationCentre_(cache.rotationCentre_),
+    complete_(cache.complete_),
+    index0_(cache.index0_),
+    index1_(cache.index1_),
+    interpWeight_(cache.interpWeight_),
+    coordSysPtr_(nullptr),  // Need to clone as cylindricalCS
+    theta_(cache.theta_),
+    cachedSrcAddress_(cache.cachedSrcAddress_),
+    cachedSrcWeights_(cache.cachedSrcWeights_),
+    cachedSrcWeightsSum_(cache.cachedSrcWeightsSum_),
+    cachedSrcMapPtr_(cache.cachedSrcMapPtr_.size()),  // Need to clone
+    cachedTgtAddress_(cache.cachedTgtAddress_),
+    cachedTgtWeights_(cache.cachedTgtWeights_),
+    cachedTgtWeightsSum_(cache.cachedTgtWeightsSum_),
+    cachedTgtMapPtr_(cache.cachedTgtMapPtr_.size()),  // Need to clone
+    toSource_(cache.toSource_)
+{
+    if (cache.coordSysPtr_)
+    {
+        coordSysPtr_.reset(new coordSystem::cylindrical(cache.coordSysPtr_()));
+    }
+
+    forAll(cachedSrcMapPtr_, cachei)
+    {
+        cachedSrcMapPtr_[cachei].reset(cache.cachedSrcMapPtr_[cachei].clone());
+    }
+
+    forAll(cachedTgtMapPtr_, cachei)
+    {
+        cachedTgtMapPtr_[cachei].reset(cache.cachedTgtMapPtr_[cachei].clone());
+    }
+}
+
+
+Foam::AMICache::AMICache
+(
+    const AMICache& cache,
+    const AMIInterpolation& fineAMI,
+    const labelList& sourceRestrictAddressing,
+    const labelList& targetRestrictAddressing
+)
+:
+    size_(cache.size_),
+    rotationAxis_(cache.rotationAxis_),
+    rotationCentre_(cache.rotationCentre_),
+    complete_(cache.complete_),
+    index0_(cache.index0_),
+    index1_(cache.index1_),
+    interpWeight_(cache.interpWeight_),
+    coordSysPtr_(nullptr),
+    theta_(cache.theta_),
+    cachedSrcAddress_(cache.size_),
+    cachedSrcWeights_(cache.size_),
+    cachedSrcWeightsSum_(cache.size_),
+    cachedSrcMapPtr_(cache.size_),
+    cachedTgtAddress_(cache.size_),
+    cachedTgtWeights_(cache.size_),
+    cachedTgtWeightsSum_(cache.size_),
+    cachedTgtMapPtr_(cache.size_),
+    toSource_(cache.toSource_)
+{
+    if (size_ > 0 && fineAMI.comm() != -1)
+    {
+        for (label cachei : {index0_, index1_})
+        {
+            if (cachei == -1) continue;
+
+            scalarField dummySrcMagSf;
+            labelListList srcAddress;
+            scalarListList srcWeights;
+            scalarField srcWeightsSum;
+            autoPtr<mapDistribute> tgtMapPtr;
+
+            AMIInterpolation::agglomerate
+            (
+                cache.cachedTgtMapPtr()[cachei],
+                fineAMI.srcMagSf(),
+                cache.cachedSrcAddress()[cachei],
+                cache.cachedSrcWeights()[cachei],
+
+                sourceRestrictAddressing,
+                targetRestrictAddressing,
+
+                dummySrcMagSf,
+                srcAddress,
+                srcWeights,
+                srcWeightsSum,
+                tgtMapPtr,
+                fineAMI.comm()
+            );
+
+            scalarField dummyTgtMagSf;
+            labelListList tgtAddress;
+            scalarListList tgtWeights;
+            scalarField tgtWeightsSum;
+            autoPtr<mapDistribute> srcMapPtr;
+
+            AMIInterpolation::agglomerate
+            (
+                cache.cachedSrcMapPtr()[cachei],
+                fineAMI.tgtMagSf(),
+                cache.cachedTgtAddress()[cachei],
+                cache.cachedTgtWeights()[cachei],
+
+                targetRestrictAddressing,
+                sourceRestrictAddressing,
+
+                dummyTgtMagSf,
+                tgtAddress,
+                tgtWeights,
+                tgtWeightsSum,
+                srcMapPtr,
+                fineAMI.comm()
+            );
+
+            cachedSrcAddress_[cachei] = srcAddress;
+            cachedSrcWeights_[cachei] = srcWeights;
+            cachedSrcWeightsSum_[cachei] = srcWeightsSum;
+            cachedSrcMapPtr_[cachei] = srcMapPtr.clone();
+
+            cachedTgtAddress_[cachei] = tgtAddress;
+            cachedTgtWeights_[cachei] = tgtWeights;
+            cachedTgtWeightsSum_[cachei] = tgtWeightsSum;
+            cachedTgtMapPtr_[cachei] = tgtMapPtr.clone();
+        }
+    }
+}
+
+
+Foam::AMICache::AMICache(Istream& is)
+:
+    size_(readLabel(is)),
+
+    rotationAxis_(is),
+    rotationCentre_(is),
+    maxThetaDeg_(readScalar(is)),
+
+    complete_(readBool(is)),
+
+    index0_(-1),
+    index1_(-1),
+    interpWeight_(0),
+    coordSysPtr_(nullptr),
+    theta_(),
+    cachedSrcAddress_(),
+    cachedSrcWeights_(),
+    cachedSrcWeightsSum_(),
+    cachedSrcMapPtr_(),
+    cachedTgtAddress_(),
+    cachedTgtWeights_(),
+    cachedTgtWeightsSum_(),
+    cachedTgtMapPtr_()
+{
+    const bitSet goodMap(is);
+
+    if (goodMap.size())
+    {
+        is >> index0_
+           >> index1_
+           >> interpWeight_
+           >> theta_;
+
+        const bool goodCoord(readBool(is));
+        if (goodCoord)
+        {
+            coordSysPtr_.reset(new coordSystem::cylindrical(is));
+        }
+
+        is >> cachedSrcAddress_
+           >> cachedSrcWeights_
+           >> cachedSrcWeightsSum_;
+
+        cachedSrcMapPtr_.setSize(goodMap.size());
+        forAll(goodMap, cachei)
+        {
+            if (goodMap[cachei])
+            {
+                cachedSrcMapPtr_[cachei].reset(new mapDistribute(is));
+            }
+        }
+
+        is >> cachedTgtAddress_
+           >> cachedTgtWeights_
+           >> cachedTgtWeightsSum_;
+
+        cachedTgtMapPtr_.setSize(goodMap.size());
+        forAll(goodMap, cachei)
+        {
+            if (goodMap[cachei])
+            {
+                cachedTgtMapPtr_[cachei].reset(new mapDistribute(is));
+            }
+        }
+    }
+}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+void Foam::AMICache::addToCache
+(
+    const AMIInterpolation& ami,
+    const point& globalPoint
+)
+{
+    DebugPout<< "-- addToCache" << endl;
+
+
+    if (!active())
+    {
+        DebugInfo<< "-- addToCache - deactivated" << endl;
+        return;
+    }
+
+    if (!coordSysPtr_)
+    {
+        DebugInfo
+            << "Creating rotation co-ordinate system:"
+            << " rotationCentre:" << rotationCentre_
+            << " rotationAxis:" << rotationAxis_
+            << " p:" << globalPoint
+            << endl;
+
+        coordSysPtr_.reset
+        (
+            new coordSystem::cylindrical(rotationCentre_, rotationAxis_)
+        );
+        DebugPout<< "Coord sys:" << coordSysPtr_() << endl;
+    }
+
+    // Check if cache is complete
+    if (!complete_)
+    {
+        for (const scalar angle : theta_)
+        {
+            // Check against null value; if any are present, cache is incomplete
+            if (angle > constant::mathematical::twoPi)
+            {
+                complete_ = false;
+                break;
+            }
+        }
+    }
+
+    if (!complete_)
+    {
+        const scalar theta = getRotationAngle(globalPoint);
+
+        const label bini = theta/constant::mathematical::twoPi*size_;
+
+        DebugPout<< "  -- bini:" << bini << " for theta:" << theta << endl;
+
+        // Check if already have entry for this bin
+        if (theta_[bini] > constant::mathematical::twoPi)
+        {
+            DebugPout<< "  -- setting cache at index " << bini << endl;
+
+            // New entry
+            theta_[bini] = theta;
+
+            cachedSrcAddress_[bini] = ami.srcAddress();
+            cachedSrcWeights_[bini] = ami.srcWeights();
+            cachedSrcWeightsSum_[bini] = ami.srcWeightsSum();
+
+            if (ami.hasSrcMap())
+            {
+                cachedSrcMapPtr_[bini] = ami.srcMap().clone();
+            }
+
+            cachedTgtAddress_[bini] = ami.tgtAddress();
+            cachedTgtWeights_[bini] = ami.tgtWeights();
+            cachedTgtWeightsSum_[bini] = ami.tgtWeightsSum();
+
+            if (ami.hasTgtMap())
+            {
+                cachedTgtMapPtr_[bini] = ami.tgtMap().clone();
+            }
+        }
+    }
+}
+
+
+bool Foam::AMICache::restoreCache(const point& globalPoint)
+{
+    DebugPout<< "-- restoreCache" << endl;
+
+    index0_ = -1;
+    index1_ = -1;
+    interpWeight_ = -1;
+
+    if (!coordSysPtr_ || size_ == -1)
+    {
+        return false;
+    }
+
+    const scalar theta = getRotationAngle(globalPoint);
+    const scalar twoPi = constant::mathematical::twoPi;
+    const label bini = theta/twoPi*size_;
+
+    DebugPout<< "  -- bini:" << bini << " for theta:" << theta << endl;
+
+    const auto validIndex = [&](const scalar bini)
+    {
+        return theta_[bini] < constant::mathematical::twoPi;
+    };
+
+    // Maximum angle in degrees for which to search for cached bins
+    const scalar maxThetaStencil = maxThetaDeg_*constant::mathematical::pi/180.0;
+
+    if
+    (
+        validIndex(bini)
+     && (
+            mag(theta - theta_[bini]) < cacheThetaTolerance_
+         || mag(theta - twoPi - theta_[bini]) < cacheThetaTolerance_
+        )
+    )
+    {
+        // Hit cached value - no interpolation needed
+        // index1_ = -1 indicates no interpolation
+        index0_ = bini;
+        index1_ = -1;
+        interpWeight_ = 0;
+
+        DebugInfo
+            << "  -- t0:" << theta_[index0_] << " theta:" << theta
+            << " i0:" << index0_ << " i1:" << index1_
+            << " w:" << interpWeight_ << endl;
+        return true;
+    }
+    else
+    {
+        // Find indices and values bracketing theta
+        const label nBin = theta_.size();
+
+        // Participating theta values and bin addresses
+        // - Note we add wrap-around values at start and end
+        DynamicList<scalar> thetap(nBin+2);
+        DynamicList<label> binAddresses(nBin+2);
+
+        // Initialise wrap-around values
+        thetap.push_back(0);
+        binAddresses.push_back(-1);
+        forAll(theta_, thetai)
+        {
+            if (validIndex(thetai))
+            {
+                thetap.push_back(theta_[thetai]);
+                binAddresses.push_back(thetai);
+            }
+        }
+
+        // Check that we have enough data points for interpolation
+        // - We added storage for lower wrap-around value, and we then need
+        //   at least 2 additional values for the interpolation
+        if (thetap.size() < 3)
+        {
+            DebugPout<< "  -- no cache available" << endl;
+            return false;
+        }
+
+        // Set wrap-around values if we have sufficient data
+        thetap[0] = thetap.last() - twoPi;
+        binAddresses[0] = binAddresses.last();
+        thetap.push_back(thetap[1] + twoPi);
+        binAddresses.push_back(binAddresses[1]);
+
+        // Find interpolation indices
+        label loweri = labelMax;
+        label i = 0;
+        while (i < thetap.size())
+        {
+            if (thetap[i] < theta)
+            {
+                loweri = i;
+            }
+            else
+            {
+                break;
+            }
+            ++i;
+        }
+
+        if (loweri == labelMax)
+        {
+            DebugPout<< "  -- no cache available" << endl;
+            return false;
+        }
+
+        label upperi = labelMax;
+        i = thetap.size() - 1;
+        while (i >= 0)
+        {
+            if (thetap[i] > theta)
+            {
+                upperi = i;
+            }
+            else
+            {
+                break;
+            }
+            --i;
+        }
+
+        if (upperi == labelMax)
+        {
+            DebugPout<< "  -- no cache available" << endl;
+            return false;
+        }
+
+        // Ensure distances are valid
+        if (upperi == loweri)
+        {
+            DebugPout
+                << "  -- no cache available: theta:" << theta
+                << " lower:" << loweri << " upper:" << upperi << endl;
+            return false;
+        }
+        if (mag(theta - thetap[loweri]) > maxThetaStencil)
+        {
+            DebugPout
+                << "  -- no cache available: theta:" << theta
+                << " lower:" << thetap[loweri] << endl;
+            return false;
+        }
+        if (mag(theta - thetap[upperi]) > maxThetaStencil)
+        {
+            DebugPout
+                << "  -- no cache available: theta:" << theta
+                << " upper:" << thetap[upperi] << endl;
+            return false;
+        }
+
+        index0_ = binAddresses[loweri];
+        index1_ = binAddresses[upperi];
+        interpWeight_ =
+            (theta - theta_[index0_])/(theta_[index1_] - theta_[index0_]);
+
+        DebugInfo
+            << theta_.size()
+            << "  -- t0:" << theta_[index0_] << " theta:" << theta
+            << " t1:" << theta_[index1_]
+            << " i0:" << index0_ << " i1:" << index1_
+            << " w:" << interpWeight_ << endl;
+
+
+        return true;
+    }
+
+    // If we get here then no valid cache found within stencil
+    DebugPout<< "  -- no cache available" << endl;
+    return false;
+}
+
+
+void Foam::AMICache::write(Ostream& os) const
+{
+    if (size_ > 0)
+    {
+        os.writeEntry("cacheSize", size_);
+        os.writeEntry("rotationAxis", rotationAxis_);
+        os.writeEntry("rotationCentre", rotationCentre_);
+        os.writeEntry("maxThetaDeg", maxThetaDeg_);
+    }
+}
+
+
+bool Foam::AMICache::writeData(Ostream& os) const
+{
+    os  << token::SPACE<< size_
+        << token::SPACE<< rotationAxis_
+        << token::SPACE<< rotationCentre_
+        << token::SPACE<< maxThetaDeg_
+        << token::SPACE<< complete_;
+
+    bitSet goodMap(cachedSrcMapPtr_.size());
+    forAll(goodMap, cachei)
+    {
+        goodMap.set(cachei, cachedSrcMapPtr_[cachei].good());
+    }
+    os  << token::SPACE << goodMap;
+
+    if (goodMap.size())
+    {
+        os  << token::SPACE << index0_
+            << token::SPACE << index1_
+            << token::SPACE << interpWeight_
+            << token::SPACE << theta_;
+
+        os  << token::SPACE << coordSysPtr_.good();
+
+        if (coordSysPtr_.good())
+        {
+            os  << token::SPACE << coordSysPtr_();
+        }
+
+        os  << token::SPACE << cachedSrcAddress_
+            << token::SPACE << cachedSrcWeights_
+            << token::SPACE << cachedSrcWeightsSum_;
+
+        for (const auto& index : goodMap)
+        {
+            os  << token::SPACE << cachedSrcMapPtr_[index]();
+        }
+
+        os  << token::SPACE << cachedTgtAddress_
+            << token::SPACE << cachedTgtWeights_
+            << token::SPACE << cachedTgtWeightsSum_;
+
+        for (const auto& index : goodMap)
+        {
+            os  << token::SPACE << cachedTgtMapPtr_[index]();
+        }
+    }
+
+    return true;
+}
+
+
+// ************************************************************************* //

src/meshTools/AMIInterpolation/AMIInterpolation/AMICache.H

@@ -0,0 +1,388 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Class
+    Foam::AMICache
+
+Description
+    Provides caching of weights and addressing to AMIInterpolation
+
+SourceFiles
+    AMICache.C
+
+SeeAlso
+    Foam::AMIInterpolation.H
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef Foam_AMICache_H
+#define Foam_AMICache_H
+
+#include "cylindricalCS.H"
+#include "mapDistribute.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+class AMIInterpolation;
+
+/*---------------------------------------------------------------------------*\
+                          Class AMICache Declaration
+\*---------------------------------------------------------------------------*/
+
+class AMICache
+{
+public:
+
+    // Public Data Types
+
+        //- Tolerance used when caching the AMI to identify e.g. if the
+        //- current rotation angle has already been captured
+        static scalar cacheThetaTolerance_;
+
+        static int debug;
+
+private:
+
+    // Private Data
+
+        //- Cache size
+        label size_;
+
+        //- Axis of rotation for rotational cyclics
+        vector rotationAxis_;
+
+        //- Point on axis of rotation for rotational cyclics
+        point rotationCentre_;
+
+        //- Maximum angle in degrees for which to search for cached bins
+        scalar maxThetaDeg_;
+
+        //- Flag to indicate that the cache is complete
+        bool complete_;
+
+        //- Cache index 0 in lists
+        label index0_;
+
+        //- Cache index 1 in lists
+        label index1_;
+
+        //- Interpolation weight between cache indices 0 and 1
+        scalar interpWeight_;
+
+        //- Local co-ordinate system
+        autoPtr<coordSystem::cylindrical> coordSysPtr_;
+
+        //- List of cached angle snapshots
+        List<scalar> theta_;
+
+        //- List of source addresses
+        List<labelListList> cachedSrcAddress_;
+
+        //- List of source weights
+        List<scalarListList> cachedSrcWeights_;
+
+        //- List of source weights sums
+        List<scalarField> cachedSrcWeightsSum_;
+
+        //- List of source parallel maps
+        List<autoPtr<mapDistribute>> cachedSrcMapPtr_;
+
+        //- List of target addresses
+        List<labelListList> cachedTgtAddress_;
+
+        //- List of target weights
+        List<scalarListList> cachedTgtWeights_;
+
+        //- List of target weights sums
+        List<scalarField> cachedTgtWeightsSum_;
+
+        //- List of target parallel maps
+        List<autoPtr<mapDistribute>> cachedTgtMapPtr_;
+
+
+        //- Flag to indicate interpolation direction
+        mutable bool toSource_;
+
+
+    // Private Member Functions
+
+        //- Get rotation angle for point using local co-ordinate system
+        scalar getRotationAngle(const point& globalPoint) const;
+
+
+public:
+
+    // Constructors
+
+        //- Null constructor
+        AMICache(const bool toSource = true);
+
+        //- Construct from dictionary
+        AMICache(const dictionary& dict, const bool toSource = true);
+
+        //- Construct as copy
+        AMICache(const AMICache& cache);
+
+        //- Construct from agglomeration of AMIInterpolation. Agglomeration
+        //- passed in as new coarse size and addressing from fine from coarse
+        AMICache
+        (
+            const AMICache& cache,
+            const AMIInterpolation& fineAMI,
+            const labelList& sourceRestrictAddressing,
+            const labelList& targetRestrictAddressing
+        );
+
+        //- Construct from stream
+        AMICache(Istream& is);
+
+
+    // Member Functions
+
+        //- Return true if cache is active
+        constexpr bool active() const noexcept { return size_ > 0; }
+
+        //- Return cache size
+        constexpr label size() const noexcept { return size_; }
+
+        //- Return true if cache is complete
+        constexpr bool complete() const noexcept { return complete_; }
+
+        //- Return cache lower bound index
+        constexpr label index0() const noexcept { return index0_; }
+
+        //- Return cache upper bound index
+        constexpr label index1() const noexcept { return index1_; }
+
+        //- Return cache interpolation weight
+        constexpr label weight() const noexcept { return interpWeight_; }
+
+        //- Return list of cached rotation angles
+        const List<scalar>& theta() const noexcept { return theta_; }
+
+        //- Return List of source addresses
+        const List<labelListList>& cachedSrcAddress() const noexcept
+        {
+            return cachedSrcAddress_;
+        }
+
+        //- Return List of source weights
+        const List<scalarListList>& cachedSrcWeights() const noexcept
+        {
+            return cachedSrcWeights_;
+        }
+
+        //- Return List of source weights sums
+        const List<scalarField>& cachedSrcWeightsSum() const noexcept
+        {
+            return cachedSrcWeightsSum_;
+        }
+
+        //- Return List of source parallel maps
+        const List<autoPtr<mapDistribute>>& cachedSrcMapPtr() const noexcept
+        {
+            return cachedSrcMapPtr_;
+        }
+
+        //- Return List of target addresses
+        const List<labelListList>& cachedTgtAddress() const noexcept
+        {
+            return cachedTgtAddress_;
+        }
+
+        //- Return List of target weights
+        const List<scalarListList>& cachedTgtWeights() const noexcept
+        {
+            return cachedTgtWeights_;
+        }
+
+        //- Return List of target weights sums
+        const List<scalarField>& cachedTgtWeightsSum() const noexcept
+        {
+            return cachedTgtWeightsSum_;
+        }
+
+        //- Return List of target parallel maps
+        const List<autoPtr<mapDistribute>>& cachedTgtMapPtr() const noexcept
+        {
+            return cachedTgtMapPtr_;
+        }
+
+        //- Apply cached evaluation based on user supplied evaluation function
+        template<class Type, class EvalFunction>
+        bool apply(List<Type>& result, const EvalFunction& eval) const;
+
+        //- Flag that lower bound is applicable
+        constexpr bool applyLower() const noexcept
+        {
+            return index0_ != -1 && index1_ == -1;
+        }
+
+        //- Flag that upper bound is applicable
+        constexpr bool applyUpper() const noexcept
+        {
+            return index0_ == -1 && index1_ != -1;
+        }
+
+        //- Flag that interpolation is applicable
+        constexpr bool applyInterpolate() const noexcept
+        {
+            return index0_ != -1 && index1_ != -1;
+        }
+
+        //- Set the interpolation direction
+        constexpr bool setDirection(bool toSource) const noexcept
+        {
+            toSource_ = toSource;
+            return toSource_;
+        }
+
+        //- Restore AMI weights and addressing from the cache
+        bool restoreCache(const point& globalPoint);
+
+        //- Add AMI weights and addressing to the cache
+        void addToCache
+        (
+            const AMIInterpolation& ami,
+            const point& globalPoint
+        );
+
+        //- Check cache index is valid
+        void checkIndex(const label index) const
+        {
+            if ((index < 0) || (index > size_-1))
+            {
+                FatalErrorInFunction
+                    << "Supplied out of bounds: " << index << "/"
+                    << size_ << abort(FatalError);
+            }
+        }
+
+
+        // Helper functions to retrieve cached values at index0 and index1
+        // Note: uses interpolation direction toSource_
+        #undef  defineMethods01
+        #define defineMethods01(Src, Tgt, idx)                                 \
+            const labelListList& c##Src##Address##idx() const                  \
+            {                                                                  \
+                checkIndex(index##idx##_);                                     \
+                return toSource_ ?                                             \
+                    cached##Src##Address_[index##idx##_]                       \
+                  : cached##Tgt##Address_[index##idx##_];                      \
+            }                                                                  \
+            const scalarListList& c##Src##Weights##idx() const                 \
+            {                                                                  \
+                checkIndex(index##idx##_);                                     \
+                return toSource_ ?                                             \
+                    cached##Src##Weights_[index##idx##_]                       \
+                  : cached##Tgt##Weights_[index##idx##_];                      \
+            }                                                                  \
+            const scalarField& c##Src##WeightsSum##idx() const                 \
+            {                                                                  \
+                checkIndex(index##idx##_);                                     \
+                return toSource_ ?                                             \
+                    cached##Src##WeightsSum_[index##idx##_]                    \
+                  : cached##Tgt##WeightsSum_[index##idx##_];                   \
+            }                                                                  \
+            const autoPtr<mapDistribute>& c##Src##MapPtr##idx() const          \
+            {                                                                  \
+                checkIndex(index##idx##_);                                     \
+                return toSource_ ?                                             \
+                    cached##Src##MapPtr_[index##idx##_]                        \
+                  : cached##Tgt##MapPtr_[index##idx##_];                       \
+            }
+
+        defineMethods01(Src, Tgt, 0)
+        defineMethods01(Src, Tgt, 1)
+        defineMethods01(Tgt, Src, 0)
+        defineMethods01(Tgt, Src, 1)
+
+
+        // Helper functions to retrieve cached values at supplied index
+        // Note: uses interpolation direction toSource_
+        #undef  defineMethodsIndex
+        #define defineMethodsIndex(Src, Tgt)                                   \
+            const labelListList& c##Src##Address(const label index) const      \
+            {                                                                  \
+                checkIndex(index);                                             \
+                return toSource_ ?                                             \
+                    cached##Src##Address_[index]                               \
+                  : cached##Tgt##Address_[index];                              \
+            }                                                                  \
+            const scalarListList& c##Src##Weights(const label index) const     \
+            {                                                                  \
+                checkIndex(index);                                             \
+                return toSource_ ?                                             \
+                    cached##Src##Weights_[index]                               \
+                  : cached##Tgt##Weights_[index];                              \
+            }                                                                  \
+            const scalarField& c##Src##WeightsSum(const label index) const     \
+            {                                                                  \
+                checkIndex(index);                                             \
+                return toSource_ ?                                             \
+                    cached##Src##WeightsSum_[index]                            \
+                  : cached##Tgt##WeightsSum_[index];                           \
+            }                                                                  \
+            const autoPtr<mapDistribute>& c##Src##MapPtr(const label index)    \
+            const                                                              \
+            {                                                                  \
+                checkIndex(index);                                             \
+                return toSource_ ?                                             \
+                    cached##Src##MapPtr_[index]                                \
+                  : cached##Tgt##MapPtr_[index];                               \
+            }
+
+        defineMethodsIndex(Src, Tgt)
+        defineMethodsIndex(Tgt, Src)
+
+
+    // I-O
+
+        //- Write AMI as a dictionary
+        void write(Ostream& os) const;
+
+        //- Write AMI raw
+        bool writeData(Ostream& os) const;
+};
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#ifdef NoRepository
+    #include "AMICacheTemplates.C"
+#endif
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //

src/meshTools/AMIInterpolation/AMIInterpolation/AMICacheTemplates.C

@@ -0,0 +1,63 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | www.openfoam.com
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+    Copyright (C) 2025 OpenCFD Ltd.
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+template<class Type, class EvalFunction>
+bool Foam::AMICache::apply(List<Type>& result, const EvalFunction& eval) const
+{
+    if (applyLower())
+    {
+        eval(result, index0_);
+        return true;
+    }
+    else if (applyUpper())
+    {
+        eval(result, index1_);
+        return true;
+    }
+    else if (applyInterpolate())
+    {
+        List<Type> r0(result);
+        eval(r0, index0_);
+        List<Type> r1(result);
+        eval(r1, index1_);
+
+        //result = (r1 - r0)*interpWeight_ + r0;
+        forAll(result, i)
+        {
+            result[i] = lerp(r0[i], r1[i], interpWeight_);
+        }
+        return true;
+    }
+
+    return false;
+}
+
+
+// ************************************************************************* //

src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.C

@@ -61,11 +61,26 @@ registerOptSwitch
 
 // * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * * //
 
+void Foam::AMIInterpolation::addToCache(const point& refPt)
+{
+    DebugInfo<< "-- addToCache" << endl;
+
+    cache_.addToCache(*this, refPt);
+}
+
+
+bool Foam::AMIInterpolation::restoreCache(const point& refPt)
+{
+    DebugInfo<< "-- restoreCache" << endl;
+
+    upToDate_ = cache_.restoreCache(refPt);
+
+    return upToDate_;
+}
+
+
 Foam::autoPtr<Foam::indexedOctree<Foam::AMIInterpolation::treeType>>
-Foam::AMIInterpolation::createTree
+Foam::AMIInterpolation::createTree(const primitivePatch &patch) const
-(
-    const primitivePatch& patch
-) const
 {
     treeBoundBox bb(patch.points(), patch.meshPoints());
     bb.inflate(0.01);
@@ -700,7 +715,8 @@ Foam::AMIInterpolation::AMIInterpolation
     tgtWeightsSum_(),
     tgtCentroids_(),
     tgtMapPtr_(nullptr),
-    upToDate_(false)
+    upToDate_(false),
+    cache_(dict)
 {}
 
 
@@ -730,7 +746,8 @@ Foam::AMIInterpolation::AMIInterpolation
     tgtCentroids_(),
     tgtPatchPts_(),
     tgtMapPtr_(nullptr),
-    upToDate_(false)
+    upToDate_(false),
+    cache_()
 {}
 
 
@@ -743,7 +760,7 @@ Foam::AMIInterpolation::AMIInterpolation
 :
     requireMatch_(fineAMI.requireMatch_),
     reverseTarget_(fineAMI.reverseTarget_),
-    lowWeightCorrection_(-1.0),
+    lowWeightCorrection_(-1.0), // Deactivated?
     singlePatchProc_(fineAMI.singlePatchProc_),
     comm_(fineAMI.comm()),  // use fineAMI geomComm if present, comm otherwise
     geomComm_(),
@@ -759,16 +776,17 @@ Foam::AMIInterpolation::AMIInterpolation
     tgtWeightsSum_(),
     tgtPatchPts_(),
     tgtMapPtr_(nullptr),
-    upToDate_(false)
+    upToDate_(false),
+    cache_(fineAMI.cache(), fineAMI, sourceRestrictAddressing, targetRestrictAddressing)
 {
-    label sourceCoarseSize =
+    const label sourceCoarseSize =
     (
         sourceRestrictAddressing.size()
       ? max(sourceRestrictAddressing)+1
       : 0
     );
 
-    label neighbourCoarseSize =
+    const label neighbourCoarseSize =
     (
         targetRestrictAddressing.size()
       ? max(targetRestrictAddressing)+1
@@ -895,14 +913,15 @@ Foam::AMIInterpolation::AMIInterpolation(const AMIInterpolation& ami)
     srcWeights_(ami.srcWeights_),
     srcWeightsSum_(ami.srcWeightsSum_),
     srcCentroids_(ami.srcCentroids_),
-    srcMapPtr_(nullptr),
+    srcMapPtr_(ami.srcMapPtr_.clone()),
     tgtMagSf_(ami.tgtMagSf_),
     tgtAddress_(ami.tgtAddress_),
     tgtWeights_(ami.tgtWeights_),
     tgtWeightsSum_(ami.tgtWeightsSum_),
     tgtCentroids_(ami.tgtCentroids_),
-    tgtMapPtr_(nullptr),
+    tgtMapPtr_(ami.tgtMapPtr_.clone()),
-    upToDate_(false)
+    upToDate_(ami.upToDate_),
+    cache_(ami.cache_)
 {}
 
 
@@ -930,7 +949,9 @@ Foam::AMIInterpolation::AMIInterpolation(Istream& is)
     //tgtPatchPts_(is),
     tgtMapPtr_(nullptr),
 
-    upToDate_(readBool(is))
+    upToDate_(readBool(is)),
+
+    cache_(is)
 {
     // Hopefully no need to stream geomComm_ since only used in processor
     // agglomeration?
@@ -1361,7 +1382,6 @@ const
         }
         else if (ray.distance() < nearest.distance())
         {
-
             nearest = ray;
             nearestFacei = srcFacei;
         }
@@ -1539,6 +1559,8 @@ void Foam::AMIInterpolation::write(Ostream& os) const
     {
         os.writeEntry("lowWeightCorrection", lowWeightCorrection_);
     }
+
+    cache_.write(os);
 }
 
 
@@ -1564,6 +1586,8 @@ bool Foam::AMIInterpolation::writeData(Ostream& os) const
 
         << token::SPACE<< upToDate();
 
+    cache_.writeData(os);
+
     if (distributed() && comm() != -1)
     {
         os  << token::SPACE<< srcMap()

src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2016-2024 OpenCFD Ltd.
+    Copyright (C) 2016-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -61,7 +61,7 @@ SourceFiles
 #include "indexedOctree.H"
 #include "treeDataPrimitivePatch.H"
 #include "runTimeSelectionTables.H"
-
+#include "AMICache.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -78,6 +78,7 @@ public:
 
     // Public Data Types
 
+        //- Flag to store face-to-face intersection triangles; default = false
         static bool cacheIntersections_;
 
         //- Control use of local communicator for AMI communication
@@ -86,6 +87,10 @@ public:
         //  localComm : 2 : like 1 but always include master (for messages)
         static int useLocalComm_;
 
+        //- Tolerance used when caching the AMI to identify e.g. if the
+        //- current rotation angle has already been captured
+        static scalar cacheThetaTolerance_;
+
 
 protected:
 
@@ -145,7 +150,6 @@ protected:
             autoPtr<mapDistribute> srcMapPtr_;
 
 
-
         // Target patch
 
             //- Target face areas
@@ -173,9 +177,13 @@ protected:
             //- Target map pointer - parallel running only
             autoPtr<mapDistribute> tgtMapPtr_;
 
+
         //- Up-to-date flag
         bool upToDate_;
 
+        //- Cache
+        AMICache cache_;
+
 
     // Protected Member Functions
 
@@ -212,10 +220,10 @@ protected:
 
         // Access
 
-            //- Return the orginal src patch with optionally updated points
+            //- Return the original src patch with optionally updated points
             inline const primitivePatch& srcPatch0() const;
 
-            //- Return the orginal tgt patch with optionally updated points
+            //- Return the original tgt patch with optionally updated points
             inline const primitivePatch& tgtPatch0() const;
 
 
@@ -240,27 +248,6 @@ protected:
             );
 
 
-        // Constructor helpers
-
-            static void agglomerate
-            (
-                const autoPtr<mapDistribute>& targetMap,
-                const scalarList& fineSrcMagSf,
-                const labelListList& fineSrcAddress,
-                const scalarListList& fineSrcWeights,
-
-                const labelList& sourceRestrictAddressing,
-                const labelList& targetRestrictAddressing,
-
-                scalarList& srcMagSf,
-                labelListList& srcAddress,
-                scalarListList& srcWeights,
-                scalarField& srcWeightsSum,
-                autoPtr<mapDistribute>& tgtMap,
-                const label comm
-            );
-
-
 public:
 
     //- Runtime type information
@@ -366,6 +353,26 @@ public:
 
     // Member Functions
 
+        // Constructor helpers
+
+            static void agglomerate
+            (
+                const autoPtr<mapDistribute>& targetMap,
+                const scalarList& fineSrcMagSf,
+                const labelListList& fineSrcAddress,
+                const scalarListList& fineSrcWeights,
+
+                const labelList& sourceRestrictAddressing,
+                const labelList& targetRestrictAddressing,
+
+                scalarList& srcMagSf,
+                labelListList& srcAddress,
+                scalarListList& srcWeights,
+                scalarField& srcWeightsSum,
+                autoPtr<mapDistribute>& tgtMap,
+                const label comm
+            );
+
         // Access
 
             //- Is up-to-date?
@@ -379,6 +386,10 @@ public:
                 return old;
             }
 
+            //- Return a reference to the AMI cache
+            const AMICache& cache() const noexcept { return cache_; }
+            AMICache& cache() noexcept { return cache_; }
+
             //- Distributed across processors (singlePatchProc == -1)
             inline bool distributed() const noexcept;
 
@@ -411,6 +422,8 @@ public:
             //  \returns old value
             inline label comm(label communicator) noexcept;
 
+            //- Return true if caching is active
+            inline bool cacheActive() const;
 
             // Source patch
 
@@ -531,7 +544,8 @@ public:
 
             // Low-level
 
-                //- Weighted sum of contributions
+                //- Weighted sum of contributions. Note: cop operates on
+                //- single Type only.
                 template<class Type, class CombineOp>
                 static void weightedSum
                 (
@@ -545,20 +559,35 @@ public:
                     const UList<Type>& defaultValues
                 );
 
-                //- Weighted sum of contributions
+                //- Weighted sum of contributions (includes caching+interp)
+                //- (for primitive types only)
                 template<class Type>
                 void weightedSum
                 (
-                    const bool interpolateToSource,
+                    const bool toSource,
                     const UList<Type>& fld,
                     List<Type>& result,
                     const UList<Type>& defaultValues
                 ) const;
 
-                //- Interpolate from target to source with supplied op
+                //- Weighted sum of (potentially distributed) contributions
+                //- and apply caching+interpolation. Note: iop
+                //- operates on single Type only
+                template<class Type, class CombineOp, class InterpolateOp>
+                void interpolate
+                (
+                    const bool toSource,
+                    const UList<Type>& fld,
+                    const CombineOp& cop,
+                    const InterpolateOp& iop,
+                    List<Type>& result,
+                    const UList<Type>& defaultValues
+                ) const;
+
+                //- Interpolate from source to target with supplied op
                 //- to combine existing value with remote value and weight
                 template<class Type, class CombineOp>
-                void interpolateToSource
+                void interpolateToTarget
                 (
                     const UList<Type>& fld,
                     const CombineOp& cop,
@@ -566,10 +595,10 @@ public:
                     const UList<Type>& defaultValues = UList<Type>::null()
                 ) const;
 
-                //- Interpolate from source to target with supplied op
+                //- Interpolate from target to source with supplied op
                 //- to combine existing value with remote value and weight
                 template<class Type, class CombineOp>
-                void interpolateToTarget
+                void interpolateToSource
                 (
                     const UList<Type>& fld,
                     const CombineOp& cop,
@@ -671,6 +700,12 @@ public:
             )
             const;
 
+            //- Restore AMI weights and addressing from the cache
+            bool restoreCache(const point& refPt);
+
+            //- Add AMI weights and addressing to the cache
+            void addToCache(const point& refPt);
+
 
         // Checks
 

src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolationI.H

@@ -123,6 +123,12 @@ inline Foam::label Foam::AMIInterpolation::comm(label communicator) noexcept
 }
 
 
+inline bool Foam::AMIInterpolation::cacheActive() const
+{
+    return cache_.active();
+}
+
+
 inline const Foam::List<Foam::scalar>& Foam::AMIInterpolation::srcMagSf() const
 {
     return srcMagSf_;

src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolationTemplates.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2015-2023 OpenCFD Ltd.
+    Copyright (C) 2015-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -83,18 +83,19 @@ void Foam::AMIInterpolation::weightedSum
 template<class Type>
 void Foam::AMIInterpolation::weightedSum
 (
-    const bool interpolateToSource,
+    const bool toSource,
     const UList<Type>& fld,
     List<Type>& result,
     const UList<Type>& defaultValues
 ) const
 {
+    // Note: using non-caching AMI
     weightedSum
     (
         lowWeightCorrection_,
-        (interpolateToSource ? srcAddress_ : tgtAddress_),
+        (toSource ? srcAddress_ : tgtAddress_),
-        (interpolateToSource ? srcWeights_ : tgtWeights_),
+        (toSource ? srcWeights_ : tgtWeights_),
-        (interpolateToSource ? srcWeightsSum_ : tgtWeightsSum_),
+        (toSource ? srcWeightsSum_ : tgtWeightsSum_),
         fld,
         multiplyWeightedOp<Type, plusEqOp<Type>>(plusEqOp<Type>()),
         result,
@@ -103,48 +104,81 @@ void Foam::AMIInterpolation::weightedSum
 }
 
 
-template<class Type, class CombineOp>
+template<class Type, class CombineOp, class InterpolateOp>
-void Foam::AMIInterpolation::interpolateToTarget
+void Foam::AMIInterpolation::interpolate
 (
+    const bool toSource,
     const UList<Type>& fld,
     const CombineOp& cop,
+    const InterpolateOp& iop,
     List<Type>& result,
     const UList<Type>& defaultValues
 ) const
 {
-    addProfiling(ami, "AMIInterpolation::interpolateToTarget");
+    // Note
+    // - behaves as old AMIInterpolation::interpolateToSource if toSource=true
+    // - `result` should be preallocated to correct size and initialized to
+    //   an appropriate value (e.g. Zero)
 
-    if (fld.size() != srcAddress_.size())
+    // Get data locally and do a weighted sum
+
+    addProfiling(ami, "AMIInterpolation::interpolate");
+
+    cache_.setDirection(toSource);
+
+    auto checkSizes = [&](
+        const UList<Type>& fld,
+        const labelListList& srcAddr,
+        const labelListList& tgtAddr,
+        const UList<Type>& defVals
+    )
+    {
+
+        if (fld.size() != tgtAddr.size())
         {
             FatalErrorInFunction
-            << "Supplied field size is not equal to source patch size" << nl
+                << "Supplied field size is not equal to "
-            << "    source patch   = " << srcAddress_.size() << nl
+                << (toSource ? "target" : "source") << " patch size" << nl
-            << "    target patch   = " << tgtAddress_.size() << nl
+                << "    source patch   = " << srcAddr.size() << nl
+                << "    target patch   = " << tgtAddr.size() << nl
                 << "    supplied field = " << fld.size()
                 << abort(FatalError);
         }
         else if
         (
-        (lowWeightCorrection_ > 0)
+            (lowWeightCorrection_ > 0) && (defVals.size() != srcAddr.size())
-     && (defaultValues.size() != tgtAddress_.size())
         )
         {
             FatalErrorInFunction
                 << "Employing default values when sum of weights falls below "
                 << lowWeightCorrection_
-            << " but supplied default field size is not equal to target "
+                << " but number of default values is not equal to "
-            << "patch size" << nl
+                << (toSource ? "source" : "target") << " patch size" << nl
-            << "    default values = " << defaultValues.size() << nl
+                << "    default values = " << defVals.size() << nl
-            << "    target patch   = " << tgtAddress_.size() << nl
+                << "    source patch   = " << srcAddr.size() << nl
                 << abort(FatalError);
         }
+    };
 
-    result.setSize(tgtAddress_.size());
+
+    // Work space for if distributed
     List<Type> work;
 
-    if (distributed() && srcMapPtr_)
+    List<Type> result0;
+    if (cache_.index0() != -1)
     {
-        const mapDistribute& map = srcMapPtr_();
+        result0 = result;
+
+        const auto& srcAddress = cache_.cSrcAddress0();
+        const auto& srcWeights = cache_.cSrcWeights0();
+        const auto& srcWeightsSum = cache_.cSrcWeightsSum0();
+        const auto& tgtAddress = cache_.cTgtAddress0();
+
+        checkSizes(fld, srcAddress, tgtAddress, defaultValues);
+
+        if (distributed() && cache_.cTgtMapPtr0())
+        {
+            const mapDistribute& map = cache_.cTgtMapPtr0()();
 
             if (map.comm() == -1)
             {
@@ -156,14 +190,171 @@ void Foam::AMIInterpolation::interpolateToTarget
             map.distribute(work);
         }
 
+        // if constexpr (is_contiguous_scalar<Type>::value)
+        // {
+        //     result0 = Zero;
+        // }
+
         weightedSum
         (
             lowWeightCorrection_,
-        tgtAddress_,
+            srcAddress,
-        tgtWeights_,
+            srcWeights,
-        tgtWeightsSum_,
+            srcWeightsSum,
             (distributed() ? work : fld),
             cop,
+            result0,
+            defaultValues
+        );
+    }
+
+    List<Type> result1;
+    if (cache_.index1() != -1)
+    {
+        result1 = result;
+
+        const auto& srcAddress = cache_.cSrcAddress1();
+        const auto& srcWeights = cache_.cSrcWeights1();
+        const auto& srcWeightsSum = cache_.cSrcWeightsSum1();
+        const auto& tgtAddress = cache_.cTgtAddress1();
+
+        checkSizes(fld, srcAddress, tgtAddress, defaultValues);
+
+        if (distributed() && cache_.cTgtMapPtr1())
+        {
+            const mapDistribute& map = cache_.cTgtMapPtr1()();
+
+            if (map.comm() == -1)
+            {
+                return;
+            }
+
+            work.resize_nocopy(map.constructSize());
+            SubList<Type>(work, fld.size()) = fld;  // deep copy
+            map.distribute(work);
+        }
+
+        // if constexpr (is_contiguous_scalar<Type>::value)
+        // {
+        //     result1 = Zero;
+        // }
+
+        weightedSum
+        (
+            lowWeightCorrection_,
+            srcAddress,
+            srcWeights,
+            srcWeightsSum,
+            (distributed() ? work : fld),
+            cop,
+            result1,
+            defaultValues
+        );
+    }
+
+    if (cache_.applyLower())
+    {
+        result = result0;
+    }
+    else if (cache_.applyUpper())
+    {
+        result = result1;
+    }
+    else if (cache_.applyInterpolate())
+    {
+        forAll(result, i)
+        {
+            iop(result[i], i, i, result0[i], i, result1[i], cache_.weight());
+        }
+    }
+    else
+    {
+        // No cache - evaluate the AMI
+
+        const auto& srcAddress = (toSource ? srcAddress_ : tgtAddress_);
+        const auto& srcWeights = (toSource ? srcWeights_ : tgtWeights_);
+        const auto& srcWeightsSum =
+            (toSource ? srcWeightsSum_ : tgtWeightsSum_);
+        const auto& tgtAddress = (toSource ? tgtAddress_ : srcAddress_);
+
+        checkSizes(fld, srcAddress, tgtAddress, defaultValues);
+
+        if (distributed() && tgtMapPtr_)
+        {
+            const mapDistribute& map =
+            (
+                toSource
+              ? tgtMapPtr_()
+              : srcMapPtr_()
+            );
+
+            if (map.comm() == -1)
+            {
+                return;
+            }
+
+            work.resize_nocopy(map.constructSize());
+            SubList<Type>(work, fld.size()) = fld;  // deep copy
+            map.distribute(work);
+        }
+
+        // result.resize_nocopy(srcAddress.size());
+
+        // if constexpr (is_contiguous_scalar<Type>::value)
+        // {
+        //     result = Zero;
+        // }
+
+        weightedSum
+        (
+            lowWeightCorrection_,
+            srcAddress,
+            srcWeights,
+            srcWeightsSum,
+            (distributed() ? work : fld),
+            cop,
+            result,
+            defaultValues
+        );
+    }
+}
+
+
+// Leave API intact below!
+template<class Type, class CombineOp>
+void Foam::AMIInterpolation::interpolateToTarget
+(
+    const UList<Type>& fld,
+    const CombineOp& cop,
+    List<Type>& result,
+    const UList<Type>& defaultValues
+) const
+{
+    // In-place interpolation
+
+    addProfiling(ami, "AMIInterpolation::interpolateToTarget");
+
+    // Wrap lerp operator to operate inplace
+    auto iop = [&]
+    (
+        Type& res,
+        const label i,
+        const label ia,
+        const Type& a,
+        const label ib,
+        const Type& b,
+        const scalar w
+    )
+    {
+        res = lerp(a, b, w);
+    };
+
+    interpolate
+    (
+        false,                  // interpolate to target
+        fld,
+        cop,
+        iop,
         result,
         defaultValues
     );
@@ -179,58 +370,32 @@ void Foam::AMIInterpolation::interpolateToSource
     const UList<Type>& defaultValues
 ) const
 {
+    // In-place interpolation
+
     addProfiling(ami, "AMIInterpolation::interpolateToSource");
 
-    if (fld.size() != tgtAddress_.size())
+    // Wrap lerp operator to operate inplace
-    {
+    auto iop = [&]
-        FatalErrorInFunction
-            << "Supplied field size is not equal to target patch size" << nl
-            << "    source patch   = " << srcAddress_.size() << nl
-            << "    target patch   = " << tgtAddress_.size() << nl
-            << "    supplied field = " << fld.size()
-            << abort(FatalError);
-    }
-    else if
     (
-        (lowWeightCorrection_ > 0)
+        Type& res,
-     && (defaultValues.size() != srcAddress_.size())
+        const label i,
+        const label ia,
+        const Type& a,
+        const label ib,
+        const Type& b,
+        const scalar w
     )
     {
-        FatalErrorInFunction
+        res = lerp(a, b, w);
-            << "Employing default values when sum of weights falls below "
+    };
-            << lowWeightCorrection_
-            << " but number of default values is not equal to source "
-            << "patch size" << nl
-            << "    default values = " << defaultValues.size() << nl
-            << "    source patch   = " << srcAddress_.size() << nl
-            << abort(FatalError);
-    }
 
-    result.setSize(srcAddress_.size());
-    List<Type> work;
 
-    if (distributed() && tgtMapPtr_)
+    interpolate
-    {
-        const mapDistribute& map = tgtMapPtr_();
-
-        if (map.comm() == -1)
-        {
-            return;
-        }
-
-        work.resize_nocopy(map.constructSize());
-        SubList<Type>(work, fld.size()) = fld;  // deep copy
-        map.distribute(work);
-    }
-
-    weightedSum
     (
-        lowWeightCorrection_,
+        true,                   // toSource,
-        srcAddress_,
+        fld,
-        srcWeights_,
-        srcWeightsSum_,
-        (distributed() ? work : fld),
         cop,
+        iop,
         result,
         defaultValues
     );

src/meshTools/AMIInterpolation/GAMG/interfaceFields/cyclicACMIGAMGInterfaceField/cyclicACMIGAMGInterfaceField.C

@@ -67,9 +67,7 @@ Foam::cyclicACMIGAMGInterfaceField::cyclicACMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, fineInterface),
     cyclicACMIInterface_(refCast<const cyclicACMIGAMGInterface>(GAMGCp)),
     doTransform_(false),
-    rank_(0),
+    rank_(0)
-    sendRequests_(),
-    recvRequests_()
 {
     const cyclicAMILduInterfaceField& p =
         refCast<const cyclicAMILduInterfaceField>(fineInterface);
@@ -89,9 +87,7 @@ Foam::cyclicACMIGAMGInterfaceField::cyclicACMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, doTransform, rank),
     cyclicACMIInterface_(refCast<const cyclicACMIGAMGInterface>(GAMGCp)),
     doTransform_(doTransform),
-    rank_(rank),
+    rank_(rank)
-    sendRequests_(),
-    recvRequests_()
 {}
 
 
@@ -104,9 +100,7 @@ Foam::cyclicACMIGAMGInterfaceField::cyclicACMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, is),
     cyclicACMIInterface_(refCast<const cyclicACMIGAMGInterface>(GAMGCp)),
     doTransform_(readBool(is)),
-    rank_(readLabel(is)),
+    rank_(readLabel(is))
-    sendRequests_(),
-    recvRequests_()
 {}
 
 
@@ -120,9 +114,7 @@ Foam::cyclicACMIGAMGInterfaceField::cyclicACMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, local),
     cyclicACMIInterface_(refCast<const cyclicACMIGAMGInterface>(GAMGCp)),
     doTransform_(false),
-    rank_(0),
+    rank_(0)
-    sendRequests_(),
-    recvRequests_()
 {
     const auto& p = refCast<const cyclicACMILduInterfaceField>(local);
 
@@ -142,9 +134,15 @@ bool Foam::cyclicACMIGAMGInterfaceField::ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if
         (
@@ -153,9 +151,15 @@ bool Foam::cyclicACMIGAMGInterfaceField::ready() const
                 sendRequests_.start(),
                 sendRequests_.size()
             )
+         && UPstream::finishedRequests
+            (
+                sendRequests1_.start(),
+                sendRequests1_.size()
+            )
         )
         {
             sendRequests_.clear();
+            sendRequests1_.clear();
         }
 
         return true;
@@ -210,15 +214,9 @@ void Foam::cyclicACMIGAMGInterfaceField::initInterfaceMatrixUpdate
         // Transform according to the transformation tensors
         transformCoupleField(pnf, cmpt);
 
-        const auto& map =
-        (
-            cyclicACMIInterface_.owner()
-          ? AMI.tgtMap()
-          : AMI.srcMap()
-        );
 
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -226,8 +224,16 @@ void Foam::cyclicACMIGAMGInterfaceField::initInterfaceMatrixUpdate
                 << abort(FatalError);
         }
 
-        // Assume that sends are also OK
+        const auto& cache = AMI.cache();
-        sendRequests_.clear();
+
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
+            const auto& map =
+            (
+                cyclicACMIInterface_.owner()
+              ? AMI.tgtMap()
+              : AMI.srcMap()
+            );
 
             // Insert send/receive requests (non-blocking). See e.g.
             // cyclicAMIPolyPatchTemplates.C
@@ -243,6 +249,39 @@ void Foam::cyclicACMIGAMGInterfaceField::initInterfaceMatrixUpdate
             );
             UPstream::commWarn(oldWarnComm);
         }
+        else
+        {
+            cache.setDirection(cyclicACMIInterface_.owner());
+
+            if (cache.index0() != -1)
+            {
+                const auto& map0 = cache.cTgtMapPtr0()();
+                map0.send
+                (
+                    pnf,
+                    sendRequests_,
+                    scalarSendBufs_,
+                    recvRequests_,
+                    scalarRecvBufs_,
+                    19462+cyclicACMIInterface_.index()   // unique offset + patch index
+                );
+            }
+
+            if (cache.index1() != -1)
+            {
+                const auto& map1 = cache.cTgtMapPtr1()();
+                map1.send
+                (
+                    pnf,
+                    sendRequests1_,
+                    scalarSendBufs1_,
+                    recvRequests1_,
+                    scalarRecvBufs1_,
+                    19463+cyclicACMIInterface_.index()   // unique offset + patch index
+                );
+            }
+        }
+    }
 
     this->updatedMatrix(false);
 }
@@ -260,6 +299,8 @@ void Foam::cyclicACMIGAMGInterfaceField::updateInterfaceMatrix
     const Pstream::commsTypes
 ) const
 {
+    typedef multiplyWeightedOp<scalar, plusEqOp<scalar>> opType;
+
     const labelUList& faceCells = lduAddr.patchAddr(patchId);
 
     const auto& AMI =
@@ -269,15 +310,11 @@ void Foam::cyclicACMIGAMGInterfaceField::updateInterfaceMatrix
       : cyclicACMIInterface_.neighbPatch().AMI()
     );
 
-    DebugPout<< "cyclicACMIGAMGInterfaceField::updateInterfaceMatrix() :"
+    const auto& cache = AMI.cache();
-        << " interface:" << cyclicACMIInterface_.index()
-        << " size:" << cyclicACMIInterface_.size()
-        << " owner:" << cyclicACMIInterface_.owner()
-        << " AMI distributed:" << AMI.distributed()
-        << endl;
-
 
     if (AMI.distributed() && AMI.comm() != -1)
+    {
+        if (cache.index0() == -1 && cache.index1() == -1)
         {
             const auto& map =
             (
@@ -313,29 +350,157 @@ void Foam::cyclicACMIGAMGInterfaceField::updateInterfaceMatrix
             this->addToInternalField(result, !add, faceCells, coeffs, pnf);
         }
         else
+        {
+            cache.setDirection(cyclicACMIInterface_.owner());
+
+            solveScalarField pnf(faceCells.size());
+            solveScalarField work(faceCells.size());
+
+            if (cache.index0() != -1)
+            {
+                // Receive (= copy) data from buffers into work. TBD: receive directly
+                // into slices of work.
+                work = Zero;
+                cache.cTgtMapPtr0()().receive
+                (
+                    recvRequests_,
+                    scalarRecvBufs_,
+                    work,
+                    19462+cyclicACMIInterface_.index()   // unique offset + patch index
+                );
+
+                // Receive requests all handled by last function call
+                recvRequests_.clear();
+
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress0(),
+                    cache.cSrcWeights0(),
+                    cache.cSrcWeightsSum0(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    solveScalarField::null()
+                );
+
+                pnf *= (1-cache.weight());
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+
+            if (cache.index1() != -1)
+            {
+                // Receive (= copy) data from buffers into work. TBD: receive directly
+                // into slices of work.
+                work = Zero;
+                cache.cTgtMapPtr1()().receive
+                (
+                    recvRequests1_,
+                    scalarRecvBufs1_,
+                    work,
+                    19463+cyclicACMIInterface_.index()   // unique offset + patch index
+                );
+
+                // Receive requests all handled by last function call
+                recvRequests1_.clear();
+
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress1(),
+                    cache.cSrcWeights1(),
+                    cache.cSrcWeightsSum1(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    solveScalarField::null()
+                );
+
+                pnf *= cache.weight();
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+        }
+    }
+    else
     {
         // Get neighbouring field
         const labelUList& nbrFaceCells =
             lduAddr.patchAddr(cyclicACMIInterface_.neighbPatchID());
 
-        solveScalarField pnf(psiInternal, nbrFaceCells);
+        solveScalarField work(psiInternal, nbrFaceCells);
 
         // Transform according to the transformation tensors
-        transformCoupleField(pnf, cmpt);
+        transformCoupleField(work, cmpt);
 
-        if (cyclicACMIInterface_.owner())
+        if (cache.index0() == -1 && cache.index1() == -1)
         {
-            pnf = AMI.interpolateToSource(pnf);
+            solveScalarField pnf(faceCells.size(), Zero);
-        }
+
-        else
+            AMI.weightedSum
-        {
+            (
-            pnf = AMI.interpolateToTarget(pnf);
+                cyclicACMIInterface_.owner(),
-        }
+                work,
+                pnf,                // result
+                solveScalarField::null()
+            );
 
             const labelUList& faceCells = lduAddr.patchAddr(patchId);
 
             this->addToInternalField(result, !add, faceCells, coeffs, pnf);
         }
+        else
+        {
+            cache.setDirection(cyclicACMIInterface_.owner());
+
+            solveScalarField pnf(faceCells.size());
+
+            if (cache.index0() != -1)
+            {
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress0(),
+                    cache.cSrcWeights0(),
+                    cache.cSrcWeightsSum0(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    solveScalarField::null()
+                );
+
+                pnf *= (1 - cache.weight());
+
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+
+            if (cache.index1() != -1)
+            {
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress1(),
+                    cache.cSrcWeights1(),
+                    cache.cSrcWeightsSum1(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    solveScalarField::null()
+                );
+
+                pnf *= cache.weight();
+
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+        }
+    }
 
     this->updatedMatrix(true);
 }

src/meshTools/AMIInterpolation/GAMG/interfaceFields/cyclicACMIGAMGInterfaceField/cyclicACMIGAMGInterfaceField.H

@@ -83,6 +83,20 @@ class cyclicACMIGAMGInterfaceField
             //- Scalar receive buffers
             mutable PtrList<List<solveScalar>> scalarRecvBufs_;
 
+            // Only used for AMI caching
+
+                //- Current range of send requests (non-blocking)
+                mutable labelRange sendRequests1_;
+
+                //- Current range of recv requests (non-blocking)
+                mutable labelRange recvRequests1_;
+
+                //- Scalar send buffers
+                mutable PtrList<List<solveScalar>> scalarSendBufs1_;
+
+                //- Scalar receive buffers
+                mutable PtrList<List<solveScalar>> scalarRecvBufs1_;
+
 
     // Private Member Functions
 

src/meshTools/AMIInterpolation/GAMG/interfaceFields/cyclicAMIGAMGInterfaceField/cyclicAMIGAMGInterfaceField.C

@@ -67,9 +67,7 @@ Foam::cyclicAMIGAMGInterfaceField::cyclicAMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, fineInterface),
     cyclicAMIInterface_(refCast<const cyclicAMIGAMGInterface>(GAMGCp)),
     doTransform_(false),
-    rank_(0),
+    rank_(0)
-    sendRequests_(),
-    recvRequests_()
 {
     const cyclicAMILduInterfaceField& p =
         refCast<const cyclicAMILduInterfaceField>(fineInterface);
@@ -89,9 +87,7 @@ Foam::cyclicAMIGAMGInterfaceField::cyclicAMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, doTransform, rank),
     cyclicAMIInterface_(refCast<const cyclicAMIGAMGInterface>(GAMGCp)),
     doTransform_(doTransform),
-    rank_(rank),
+    rank_(rank)
-    sendRequests_(),
-    recvRequests_()
 {}
 
 
@@ -104,9 +100,7 @@ Foam::cyclicAMIGAMGInterfaceField::cyclicAMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, is),
     cyclicAMIInterface_(refCast<const cyclicAMIGAMGInterface>(GAMGCp)),
     doTransform_(readBool(is)),
-    rank_(readLabel(is)),
+    rank_(readLabel(is))
-    sendRequests_(),
-    recvRequests_()
 {}
 
 
@@ -120,9 +114,7 @@ Foam::cyclicAMIGAMGInterfaceField::cyclicAMIGAMGInterfaceField
     GAMGInterfaceField(GAMGCp, local),
     cyclicAMIInterface_(refCast<const cyclicAMIGAMGInterface>(GAMGCp)),
     doTransform_(false),
-    rank_(0),
+    rank_(0)
-    sendRequests_(),    // assume no requests in flight for input field
-    recvRequests_()
 {
     const auto& p = refCast<const cyclicAMILduInterfaceField>(local);
 
@@ -142,9 +134,15 @@ bool Foam::cyclicAMIGAMGInterfaceField::ready() const
             recvRequests_.start(),
             recvRequests_.size()
         )
+     && UPstream::finishedRequests
+        (
+            recvRequests1_.start(),
+            recvRequests1_.size()
+        )
     )
     {
         recvRequests_.clear();
+        recvRequests1_.clear();
 
         if
         (
@@ -153,9 +151,15 @@ bool Foam::cyclicAMIGAMGInterfaceField::ready() const
                 sendRequests_.start(),
                 sendRequests_.size()
             )
+         && UPstream::finishedRequests
+            (
+                sendRequests1_.start(),
+                sendRequests1_.size()
+            )
         )
         {
             sendRequests_.clear();
+            sendRequests1_.clear();
         }
 
         return true;
@@ -183,7 +187,6 @@ void Foam::cyclicAMIGAMGInterfaceField::initInterfaceMatrixUpdate
       ? cyclicAMIInterface_.AMI()
       : cyclicAMIInterface_.neighbPatch().AMI()
     );
-
     if (AMI.distributed() && AMI.comm() != -1)
     {
         //DebugPout<< "cyclicAMIFvPatchField::initInterfaceMatrixUpdate() :"
@@ -211,15 +214,8 @@ void Foam::cyclicAMIGAMGInterfaceField::initInterfaceMatrixUpdate
         // Transform according to the transformation tensors
         transformCoupleField(pnf, cmpt);
 
-        const auto& map =
-        (
-            cyclicAMIInterface_.owner()
-          ? AMI.tgtMap()
-          : AMI.srcMap()
-        );
-
         // Assert that all receives are known to have finished
-        if (!recvRequests_.empty())
+        if (!recvRequests_.empty() || !recvRequests1_.empty())
         {
             FatalErrorInFunction
                 << "Outstanding recv request(s) on patch "
@@ -227,8 +223,16 @@ void Foam::cyclicAMIGAMGInterfaceField::initInterfaceMatrixUpdate
                 << abort(FatalError);
         }
 
-        // Assume that sends are also OK
+        const auto& cache = AMI.cache();
-        sendRequests_.clear();
+
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
+            const auto& map =
+            (
+                cyclicAMIInterface_.owner()
+              ? AMI.tgtMap()
+              : AMI.srcMap()
+            );
 
             // Insert send/receive requests (non-blocking). See e.g.
             // cyclicAMIPolyPatchTemplates.C
@@ -244,6 +248,39 @@ void Foam::cyclicAMIGAMGInterfaceField::initInterfaceMatrixUpdate
             );
             UPstream::commWarn(oldWarnComm);
         }
+        else
+        {
+            cache.setDirection(cyclicAMIInterface_.owner());
+
+            if (cache.index0() != -1)
+            {
+                const auto& map0 = cache.cTgtMapPtr0()();
+                map0.send
+                (
+                    pnf,
+                    sendRequests_,
+                    scalarSendBufs_,
+                    recvRequests_,
+                    scalarRecvBufs_,
+                    19462+cyclicAMIInterface_.index()   // unique offset + patch index
+                );
+            }
+
+            if (cache.index1() != -1)
+            {
+                const auto& map1 = cache.cTgtMapPtr1()();
+                map1.send
+                (
+                    pnf,
+                    sendRequests1_,
+                    scalarSendBufs1_,
+                    recvRequests1_,
+                    scalarRecvBufs1_,
+                    19463+cyclicAMIInterface_.index()   // unique offset + patch index
+                );
+            }
+        }
+    }
 
     this->updatedMatrix(false);
 }
@@ -261,6 +298,8 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
     const Pstream::commsTypes commsType
 ) const
 {
+    typedef multiplyWeightedOp<scalar, plusEqOp<scalar>> opType;
+
     const labelUList& faceCells = lduAddr.patchAddr(patchId);
 
     const auto& AMI =
@@ -284,6 +323,12 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
     //    << " AMI low-weight:" << AMI.applyLowWeightCorrection()
     //    << endl;
 
+    const auto& cache = AMI.cache();
+
+    // Assume that sends are also OK
+    sendRequests_.clear();
+    sendRequests1_.clear();
+
     if (AMI.distributed() && AMI.comm() != -1)
     {
         if (commsType != UPstream::commsTypes::nonBlocking)
@@ -293,6 +338,8 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
                 << exit(FatalError);
         }
 
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
             const auto& map =
             (
                 cyclicAMIInterface_.owner()
@@ -327,6 +374,84 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
             this->addToInternalField(result, !add, faceCells, coeffs, pnf);
         }
         else
+        {
+            cache.setDirection(cyclicAMIInterface_.owner());
+
+            solveScalarField pnf(faceCells.size());
+            solveScalarField work(faceCells.size());
+
+            if (cache.index0() != -1)
+            {
+                // Receive (= copy) data from buffers into work. TBD: receive directly
+                // into slices of work.
+                work = Zero;
+                cache.cTgtMapPtr0()().receive
+                (
+                    recvRequests_,
+                    scalarRecvBufs_,
+                    work,
+                    19462+cyclicAMIInterface_.index()   // unique offset + patch index
+                );
+
+                // Receive requests all handled by last function call
+                recvRequests_.clear();
+
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress0(),
+                    cache.cSrcWeights0(),
+                    cache.cSrcWeightsSum0(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    defaultValues
+                );
+
+                pnf *= (1-cache.weight());
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+
+            if (cache.index1() != -1)
+            {
+                // Receive (= copy) data from buffers into work. TBD: receive directly
+                // into slices of work.
+                work = Zero;
+                cache.cTgtMapPtr1()().receive
+                (
+                    recvRequests1_,
+                    scalarRecvBufs1_,
+                    work,
+                    19463+cyclicAMIInterface_.index()   // unique offset + patch index
+                );
+
+                // Receive requests all handled by last function call
+                recvRequests1_.clear();
+
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress1(),
+                    cache.cSrcWeights1(),
+                    cache.cSrcWeightsSum1(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    defaultValues
+                );
+
+                pnf *= cache.weight();
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+        }
+    }
+    else
     {
         // Get neighbouring field
         const labelUList& nbrFaceCells =
@@ -337,7 +462,11 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
         // Transform according to the transformation tensors
         transformCoupleField(work, cmpt);
 
-        solveScalarField pnf(faceCells.size(), Zero);
+        solveScalarField pnf(faceCells.size());
+
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
+            pnf = Zero;
             AMI.weightedSum
             (
                 cyclicAMIInterface_.owner(),
@@ -349,6 +478,53 @@ void Foam::cyclicAMIGAMGInterfaceField::updateInterfaceMatrix
             // Add result using coefficients
             this->addToInternalField(result, !add, faceCells, coeffs, pnf);
         }
+        else
+        {
+            cache.setDirection(cyclicAMIInterface_.owner());
+
+            if (cache.index0() != -1)
+            {
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress0(),
+                    cache.cSrcWeights0(),
+                    cache.cSrcWeightsSum0(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    defaultValues
+                );
+
+                pnf *= (1 - cache.weight());
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+
+            if (cache.index1() != -1)
+            {
+                pnf = Zero;
+                AMIInterpolation::weightedSum
+                (
+                    AMI.lowWeightCorrection(),
+                    cache.cSrcAddress1(),
+                    cache.cSrcWeights1(),
+                    cache.cSrcWeightsSum1(),
+                    work,
+                    opType(plusEqOp<scalar>()),
+                    pnf,
+                    defaultValues
+                );
+
+                pnf *= cache.weight();
+
+                // Add result using coefficients
+                this->addToInternalField(result, !add, faceCells, coeffs, pnf);
+            }
+        }
+    }
 
     this->updatedMatrix(true);
 }

src/meshTools/AMIInterpolation/GAMG/interfaceFields/cyclicAMIGAMGInterfaceField/cyclicAMIGAMGInterfaceField.H

@@ -83,6 +83,21 @@ class cyclicAMIGAMGInterfaceField
             mutable PtrList<List<solveScalar>> scalarRecvBufs_;
 
 
+            // Only used for AMI caching
+
+                //- Current range of send requests (non-blocking)
+                mutable labelRange sendRequests1_;
+
+                //- Current range of recv requests (non-blocking)
+                mutable labelRange recvRequests1_;
+
+                //- Scalar send buffers
+                mutable PtrList<List<solveScalar>> scalarSendBufs1_;
+
+                //- Scalar receive buffers
+                mutable PtrList<List<solveScalar>> scalarRecvBufs1_;
+
+
     // Private Member Functions
 
         //- No copy construct

src/meshTools/AMIInterpolation/patches/cyclicAMI/cyclicAMIPolyPatch/cyclicAMIPolyPatch.C

@@ -381,6 +381,46 @@ void Foam::cyclicAMIPolyPatch::resetAMI(const UList<point>& points) const
         return;
     }
 
+    point refPt = point::max;
+
+    bool restoredFromCache = false;
+    if (AMIPtr_->cacheActive())
+    {
+        const label comm = boundaryMesh().mesh().comm();
+
+        if (UPstream::parRun())
+        {
+            label refProci = -1;
+            if (size() > 0)
+            {
+                refProci = UPstream::myProcNo(comm);
+            }
+            reduce(refProci, maxOp<label>(), UPstream::msgType(), comm);
+
+            if (refProci == UPstream::myProcNo(comm))
+            {
+                refPt = points[meshPoints()[0]];
+            }
+            reduce(refPt, minOp<point>(), UPstream::msgType(), comm);
+        }
+        else
+        {
+            refPt = points[meshPoints()[0]];
+        }
+
+
+        // Sets cache indices to use and time interpolation weight
+        restoredFromCache = AMIPtr_->restoreCache(refPt);
+
+        if (returnReduceOr(restoredFromCache, comm))
+        {
+            // Restored AMI weight and addressing from cache - all done
+            Info<< "AMI: weights and addresses restored from cache" << endl;
+
+            return;
+        }
+    }
+
     const cyclicAMIPolyPatch& nbr = neighbPatch();
     const pointField srcPoints(points, meshPoints());
     pointField nbrPoints(points, nbr.meshPoints());
@@ -432,7 +472,7 @@ void Foam::cyclicAMIPolyPatch::resetAMI(const UList<point>& points) const
         meshTools::writeOBJ(osN, nbrPatch0.localFaces(), nbrPoints);
 
         OFstream osO(t.path()/name() + "_ownerPatch.obj");
-        meshTools::writeOBJ(osO, this->localFaces(), localPoints());
+        meshTools::writeOBJ(osO, this->localFaces(), srcPoints);
     }
 
     // Construct/apply AMI interpolation to determine addressing and weights
@@ -446,6 +486,8 @@ void Foam::cyclicAMIPolyPatch::resetAMI(const UList<point>& points) const
     {
         AMIPtr_->checkSymmetricWeights(true);
     }
+
+    AMIPtr_->addToCache(refPt);
 }
 
 

src/meshTools/AMIInterpolation/patches/cyclicAMI/cyclicAMIPolyPatch/cyclicAMIPolyPatch.H

@@ -99,7 +99,7 @@ protected:
         //- Index of other half
         mutable label nbrPatchID_;
 
-        //- Particle displacement fraction accross AMI
+        //- Particle displacement fraction across AMI
         const scalar fraction_;
 
 
@@ -166,6 +166,9 @@ protected:
             //- Temporary storage for AMI face centres
             mutable vectorField faceCentres0_;
 
+        // Cache
+        bool cacheAMI_;
+
 
     // Protected Member Functions
 
@@ -520,9 +523,14 @@ public:
                 (
                     const Field<Type>& fld,
                     labelRange& sendRequests,
-                    PtrList<List<Type>>& sendBuffers,
                     labelRange& recvRequests,
-                    PtrList<List<Type>>& recvBuffers
+                    PtrList<List<Type>>& sendBuffers,
+                    PtrList<List<Type>>& recvBuffers,
+
+                    labelRange& sendRequests1,
+                    labelRange& recvRequests1,
+                    PtrList<List<Type>>& sendBuffers1,
+                    PtrList<List<Type>>& recvBuffers1
                 ) const;
 
                 template<class Type>
@@ -530,9 +538,14 @@ public:
                 (
                     const Field<Type>& fld,
                     labelRange& sendRequests,
-                    PtrList<List<Type>>& sendBuffers,
                     labelRange& recvRequests,
-                    PtrList<List<Type>>& recvBuffers
+                    PtrList<List<Type>>& sendBuffers,
+                    PtrList<List<Type>>& recvBuffers,
+
+                    labelRange& sendRequests1,
+                    labelRange& recvRequests1,
+                    PtrList<List<Type>>& sendBuffers1,
+                    PtrList<List<Type>>& recvBuffers1
                 ) const;
 
                 template<class Type>
@@ -541,6 +554,8 @@ public:
                     const Field<Type>& localFld,
                     const labelRange& requests,  // The receive requests
                     const PtrList<List<Type>>& recvBuffers,
+                    const labelRange& requests1,  // The receive requests
+                    const PtrList<List<Type>>& recvBuffers1,
                     const UList<Type>& defaultValues
                 ) const;
 

src/meshTools/AMIInterpolation/patches/cyclicAMI/cyclicAMIPolyPatch/cyclicAMIPolyPatchTemplates.C

@@ -63,6 +63,7 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
 
     if constexpr (transform_supported)
     {
+        // Only creates the co-ord system if using periodic AMI
         cs.reset(cylindricalCS());
     }
 
@@ -130,7 +131,7 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
         const tensorField ownT(cs().R(this->faceCentres()));
 
         Field<Type> localDeflt(defaultValues.size());
-        if (defaultValues.size() == size())
+        if (defaultValues.size() != 0 && defaultValues.size() == size())
         {
             // Transform default values into cylindrical coords (using
             // *this faceCentres)
@@ -176,15 +177,26 @@ void Foam::cyclicAMIPolyPatch::initInterpolateUntransformed
 (
     const Field<Type>& fld,
     labelRange& sendRequests,
-    PtrList<List<Type>>& sendBuffers,
     labelRange& recvRequests,
-    PtrList<List<Type>>& recvBuffers
+    PtrList<List<Type>>& sendBuffers,
+    PtrList<List<Type>>& recvBuffers,
+
+    labelRange& sendRequests1,
+    labelRange& recvRequests1,
+    PtrList<List<Type>>& sendBuffers1,
+    PtrList<List<Type>>& recvBuffers1
 ) const
 {
     const auto& AMI = (owner() ? this->AMI() : neighbPatch().AMI());
 
     if (AMI.distributed() && AMI.comm() != -1)
     {
+        const auto& cache = AMI.cache();
+
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
+            // No caching
+
             const auto& map = (owner() ? AMI.tgtMap() : AMI.srcMap());
 
             // Insert send/receive requests (non-blocking)
@@ -198,6 +210,45 @@ void Foam::cyclicAMIPolyPatch::initInterpolateUntransformed
                 3894+this->index()  // unique offset + patch index
             );
         }
+        else
+        {
+            // Caching is active
+
+            cache.setDirection(owner());
+
+            if (cache.index0() != -1)
+            {
+                const auto& map0 = cache.cTgtMapPtr0()();
+
+                // Insert send/receive requests (non-blocking)
+                map0.send
+                (
+                    fld,
+                    sendRequests,
+                    sendBuffers,
+                    recvRequests,
+                    recvBuffers,
+                    3894+this->index()  // unique offset + patch index
+                );
+            }
+
+            if (cache.index1() != -1)
+            {
+                const auto& map1 = cache.cTgtMapPtr1()();
+
+                // Insert send/receive requests (non-blocking)
+                map1.send
+                (
+                    fld,
+                    sendRequests1,
+                    sendBuffers1,
+                    recvRequests1,
+                    recvBuffers1,
+                    3895+this->index()  // unique offset + patch index
+                );
+            }
+        }
+    }
 }
 
 
@@ -206,9 +257,14 @@ void Foam::cyclicAMIPolyPatch::initInterpolate
 (
     const Field<Type>& fld,
     labelRange& sendRequests,
-    PtrList<List<Type>>& sendBuffers,
     labelRange& recvRequests,
-    PtrList<List<Type>>& recvBuffers
+    PtrList<List<Type>>& sendBuffers,
+    PtrList<List<Type>>& recvBuffers,
+
+    labelRange& sendRequests1,
+    labelRange& recvRequests1,
+    PtrList<List<Type>>& sendBuffers1,
+    PtrList<List<Type>>& recvBuffers1
 ) const
 {
     const auto& AMI = (owner() ? this->AMI() : neighbPatch().AMI());
@@ -221,46 +277,50 @@ void Foam::cyclicAMIPolyPatch::initInterpolate
     // Can rotate fields (vector and non-spherical tensors)
     constexpr bool transform_supported = is_rotational_vectorspace_v<Type>;
 
-    [[maybe_unused]]
-    autoPtr<coordSystem::cylindrical> cs;
-
     if constexpr (transform_supported)
     {
-        cs.reset(cylindricalCS());
+        // Only creates the co-ord system if using periodic AMI
-    }
+        // - convert to cylindrical coordinate system
+        auto cs = cylindricalCS();
 
-    if (!cs)
+        if (cs)
         {
-        initInterpolateUntransformed
-        (
-            fld,
-            sendRequests,
-            sendBuffers,
-            recvRequests,
-            recvBuffers
-        );
-    }
-    else if constexpr (transform_supported)
-    {
-        const cyclicAMIPolyPatch& nbrPp = this->neighbPatch();
-
             Field<Type> localFld(fld.size());
-
+            const cyclicAMIPolyPatch& nbrPp = this->neighbPatch();
-        // Transform to cylindrical coords
-        {
             const tensorField nbrT(cs().R(nbrPp.faceCentres()));
             Foam::invTransform(localFld, nbrT, fld);
-        }
 
             initInterpolateUntransformed
             (
                 localFld,
                 sendRequests,
-            sendBuffers,
                 recvRequests,
-            recvBuffers
+                sendBuffers,
+                recvBuffers,
+
+                sendRequests1,
+                recvRequests1,
+                sendBuffers1,
+                recvBuffers1
             );
+
+            return;
         }
+    }
+
+    initInterpolateUntransformed
+    (
+        fld,
+        sendRequests,
+        recvRequests,
+        sendBuffers,
+        recvBuffers,
+
+        sendRequests1,
+        recvRequests1,
+        sendBuffers1,
+        recvBuffers1
+    );
 }
 
 
@@ -270,14 +330,21 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
     const Field<Type>& localFld,
     const labelRange& requests,
     const PtrList<List<Type>>& recvBuffers,
+    const labelRange& requests1,
+    const PtrList<List<Type>>& recvBuffers1,
     const UList<Type>& defaultValues
 ) const
 {
+    // Note: cannot be localFld.size() -> is set to null for distributed AMI
     auto tresult = tmp<Field<Type>>::New(this->size(), Zero);
 
     const auto& AMI = (owner() ? this->AMI() : neighbPatch().AMI());
 
+    const auto& cache = AMI.cache();
+    cache.setDirection(owner());
+
     Field<Type> work;
+    Field<Type> work1;
     if (AMI.distributed())
     {
         if (AMI.comm() == -1)
@@ -285,10 +352,13 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
             return tresult;
         }
 
+        if (cache.index0() == -1 && cache.index1() == -1)
+        {
+            // No caching
             const auto& map = (owner() ? AMI.tgtMap() : AMI.srcMap());
 
-        // Receive (= copy) data from buffers into work. TBD: receive directly
+            // Receive (= copy) data from buffers into work. TBD: receive
-        // into slices of work.
+            // directly into slices of work.
             map.receive
             (
                 requests,
@@ -297,35 +367,55 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
                 3894+this->index()  // unique offset + patch index
             );
         }
+        else
+        {
+            // Using AMI cache
+
+            if (cache.index0() != -1)
+            {
+                cache.cTgtMapPtr0()().receive
+                (
+                    requests,
+                    recvBuffers,
+                    work,
+                    3894+this->index()  // unique offset + patch index
+                );
+            }
+
+            if (cache.index1() != -1)
+            {
+                cache.cTgtMapPtr1()().receive
+                (
+                    requests1,
+                    recvBuffers1,
+                    work1,
+                    3895+this->index()  // unique offset + patch index
+                );
+            }
+        }
+    }
+
     const Field<Type>& fld = (AMI.distributed() ? work : localFld);
+    const Field<Type>& fld1 = (AMI.distributed() ? work1 : localFld);
 
     // Rotate fields (vector and non-spherical tensors)
     constexpr bool transform_supported = is_rotational_vectorspace_v<Type>;
 
-    [[maybe_unused]]
+    // Rotate fields (vector and non-spherical tensors) for periodic AMI
-    autoPtr<coordSystem::cylindrical> cs;
+    tensorField ownTransform;
+    Field<Type> localDeflt;
 
-    // Rotate fields (vector and non-spherical tensors)
     if constexpr (transform_supported)
     {
-        cs.reset(cylindricalCS());
+        // Only creates the co-ord system if using periodic AMI
-    }
+        // - convert to cylindrical coordinate system
+        auto cs = cylindricalCS();
 
-    if (!cs)
+        if (cs)
         {
-        AMI.weightedSum
+            ownTransform = cs().R(this->faceCentres());
-        (
+            localDeflt = defaultValues;
-            owner(),
-            fld,
-            tresult.ref(),
-            defaultValues
-        );
-    }
-    else if constexpr (transform_supported)
-    {
-        const tensorField ownT(cs().R(this->faceCentres()));
 
-        Field<Type> localDeflt(defaultValues.size());
             if (defaultValues.size() == size())
             {
                 // Transform default values into cylindrical coords (using
@@ -334,22 +424,85 @@ Foam::tmp<Foam::Field<Type>> Foam::cyclicAMIPolyPatch::interpolate
                 // Field so we can use transformField routines.
                 const SubField<Type> defaultSubFld(defaultValues);
                 const Field<Type>& defaultFld(defaultSubFld);
-            Foam::invTransform(localDeflt, ownT, defaultFld);
+                Foam::invTransform(localDeflt, ownTransform, defaultFld);
+            }
+        }
     }
 
+    const auto& localDefaultValues =
+        localDeflt.size() ? localDeflt : defaultValues;
+
+    if (cache.index0() == -1 && cache.index1() == -1)
+    {
+        // No caching
         AMI.weightedSum
         (
             owner(),
             fld,
             tresult.ref(),
-            localDeflt
+            localDefaultValues
         );
 
         // Transform back
-        Foam::transform(tresult.ref(), ownT, tresult());
+        if (ownTransform.size())
+        {
+            Foam::transform(tresult.ref(), ownTransform, tresult());
         }
 
         return tresult;
+    }
+    else
+    {
+        if (cache.index0() != -1)
+        {
+            AMIInterpolation::weightedSum
+            (
+                AMI.lowWeightCorrection(),
+                cache.cSrcAddress0(),
+                cache.cSrcWeights0(),
+                cache.cSrcWeightsSum0(),
+                fld,
+                multiplyWeightedOp<Type, plusEqOp<Type>>(plusEqOp<Type>()),
+                tresult.ref(),
+                localDefaultValues
+            );
+
+            if (ownTransform.size())
+            {
+                Foam::transform(tresult.ref(), ownTransform, tresult());
+            }
+
+            // Assuming cache weight is zero when index1 is inactive (==-1)
+            tresult.ref() *= (1 - cache.weight());
+        }
+
+        if (cache.index1() != -1)
+        {
+            auto tresult1 = tmp<Field<Type>>::New(this->size(), Zero);
+
+            AMIInterpolation::weightedSum
+            (
+                AMI.lowWeightCorrection(),
+                cache.cSrcAddress1(),
+                cache.cSrcWeights1(),
+                cache.cSrcWeightsSum1(),
+                fld1,
+                multiplyWeightedOp<Type, plusEqOp<Type>>(plusEqOp<Type>()),
+                tresult1.ref(),
+                localDefaultValues
+            );
+
+            if (ownTransform.size())
+            {
+                Foam::transform(tresult1.ref(), ownTransform, tresult1());
+            }
+
+            tresult1.ref() *= cache.weight();
+            tresult.ref() += tresult1();
+        }
+
+        return tresult;
+    }
 }
 
 

src/meshTools/Make/files

@@ -281,6 +281,7 @@ processorLOD/faceBox/faceBox.C
 AMI=AMIInterpolation
 $(AMI)/AMIInterpolation/AMIInterpolation.C
 $(AMI)/AMIInterpolation/AMIInterpolationNew.C
+$(AMI)/AMIInterpolation/AMICache.C
 $(AMI)/AMIInterpolation/advancingFrontAMI/advancingFrontAMI.C
 $(AMI)/AMIInterpolation/advancingFrontAMI/advancingFrontAMIParallelOps.C
 $(AMI)/AMIInterpolation/faceAreaWeightAMI/faceAreaWeightAMI.C

src/meshTools/algorithms/MeshWave/FaceCellWave.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2017 OpenFOAM Foundation
-    Copyright (C) 2018-2024 OpenCFD Ltd.
+    Copyright (C) 2018-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -95,6 +95,102 @@ namespace Foam
                 }
             }
     };
+
+    template<class Type, class TrackingData>
+    class interpolate
+    {
+        //- Combine operator for AMIInterpolation
+
+        FaceCellWave<Type, TrackingData>& solver_;
+
+        const cyclicAMIPolyPatch& patch_;
+
+    public:
+
+            interpolate
+            (
+                FaceCellWave<Type, TrackingData>& solver,
+                const cyclicAMIPolyPatch& patch
+            )
+            :
+                solver_(solver),
+                patch_(patch)
+            {}
+
+
+            void operator()
+            (
+                Type& x,
+                const label localFacei,
+                const label f0i,
+                const Type& y0,
+                const label f1i,
+                const Type& y1,
+                const scalar weight
+            ) const
+            {
+                if (y0.valid(solver_.data()))
+                {
+                    if (y1.valid(solver_.data()))
+                    {
+                        x.interpolate
+                        (
+                            solver_.mesh(),
+                            patch_.faceCentres()[localFacei],
+                            f0i,
+                            y0,
+                            f1i,
+                            y1,
+                            weight,
+                            solver_.propagationTol(),
+                            solver_.data()
+                        );
+                    }
+                    else
+                    {
+                        // Convert patch face into mesh face
+                        label meshFacei = -1;
+                        if (patch_.owner())
+                        {
+                            meshFacei = patch_.start() + f0i;
+                        }
+                        else
+                        {
+                            meshFacei = patch_.neighbPatch().start() + f0i;
+                        }
+                        x.updateFace
+                        (
+                            solver_.mesh(),
+                            meshFacei,
+                            y0,
+                            solver_.propagationTol(),
+                            solver_.data()
+                        );
+                    }
+                }
+                else if (y1.valid(solver_.data()))
+                {
+                    // Convert patch face into mesh face
+                    label meshFacei = -1;
+                    if (patch_.owner())
+                    {
+                        meshFacei = patch_.start() + f1i;
+                    }
+                    else
+                    {
+                        meshFacei = patch_.neighbPatch().start() + f1i;
+                    }
+                    x.updateFace
+                    (
+                        solver_.mesh(),
+                        meshFacei,
+                        y1,
+                        solver_.propagationTol(),
+                        solver_.data()
+                    );
+                }
+            }
+    };
 }
 
 
@@ -784,18 +880,43 @@ void Foam::FaceCellWave<Type, TrackingData>::handleAMICyclicPatches()
                 // Transfer sendInfo to cycPatch
                 combine<Type, TrackingData> cmb(*this, cycPatch);
 
+                // Linear interpolation
+                interpolate<Type, TrackingData> interp(*this, cycPatch);
+
+                const auto& AMI =
+                (
+                    cycPatch.owner()
+                  ? cycPatch.AMI()
+                  : cycPatch.neighbPatch().AMI()
+                );
+
                 if (cycPatch.applyLowWeightCorrection())
                 {
-                    List<Type> defVals
+                    const List<Type> defVals
                     (
                         cycPatch.patchInternalList(allCellInfo_)
                     );
-
+                    AMI.interpolate
-                    cycPatch.interpolate(sendInfo, cmb, receiveInfo, defVals);
+                    (
+                        cycPatch.owner(),
+                        sendInfo,
+                        cmb,
+                        interp,
+                        receiveInfo,
+                        defVals
+                    );
                 }
                 else
                 {
-                    cycPatch.interpolate(sendInfo, cmb, receiveInfo);
+                    AMI.interpolate
+                    (
+                        cycPatch.owner(),
+                        sendInfo,
+                        cmb,
+                        interp,
+                        receiveInfo,
+                        UList<Type>::null() // no default values needed
+                    );
                 }
             }
 

src/meshTools/cellClassification/cellInfo.H

@@ -197,6 +197,23 @@ public:
             template<class TrackingData>
             inline bool equal(const cellInfo&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const cellInfo& f0,
+                const label i1,
+                const cellInfo& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/meshTools/cellClassification/cellInfoI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -249,6 +249,31 @@ inline bool Foam::cellInfo::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::cellInfo::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const cellInfo& f0,
+    const label i1,
+    const cellInfo& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (!f0.valid(td))
+    {
+        return update(f1, -1, -1, -1, -1, td);
+    }
+    else
+    {
+        return update(f0, -1, -1, -1, -1, td);
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::cellInfo::operator==

src/meshTools/cellDist/wallPoint/wallPoint.H

@@ -76,6 +76,16 @@ class wallPoint
 
     // Private Member Functions
 
+        // Update this with w2 if distance less
+        template<class TrackingData>
+        inline bool update
+        (
+            const wallPoint& w2,
+            const scalar dist2,
+            const scalar tol,
+            TrackingData& td
+        );
+
         //- Evaluate distance to point.
         //  Update distSqr, origin from whomever is nearer pt.
         //  \return true if w2 is closer to point, false otherwise.
@@ -206,10 +216,41 @@ public:
                 TrackingData& td
             );
 
+            //- Interpolate different values
+            template<class TrackingData>
+            wallPoint
+            (
+                const polyMesh&,
+                const scalar weight,
+                const label face0,
+                const wallPoint& info0,
+                const label face1,
+                const wallPoint& info1,
+                const scalar tol,
+                TrackingData& td
+            );
+
             //- Test for equality, with TrackingData
             template<class TrackingData>
             inline bool equal(const wallPoint&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const wallPoint& f0,
+                const label i1,
+                const wallPoint& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/meshTools/cellDist/wallPoint/wallPointI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020,2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -35,21 +35,12 @@ License
 template<class TrackingData>
 inline bool Foam::wallPoint::update
 (
-    const point& pt,
     const wallPoint& w2,
+    const scalar dist2,
     const scalar tol,
     TrackingData& td
 )
 {
-    //Already done in calling algorithm
-    //if (w2.origin() == origin_)
-    //{
-    //    // Shortcut. Same input so same distance.
-    //    return false;
-    //}
-
-    const scalar dist2 = magSqr(pt - w2.origin());
-
     if (!valid(td))
     {
         // current not yet set so use any value
@@ -83,6 +74,26 @@ inline bool Foam::wallPoint::update
 }
 
 
+// Update this with w2 if w2 nearer to pt.
+template<class TrackingData>
+inline bool Foam::wallPoint::update
+(
+    const point& pt,
+    const wallPoint& w2,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    return update
+    (
+        w2,
+        magSqr(pt - w2.origin()),
+        tol,
+        td
+    );
+}
+
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 inline Foam::wallPoint::wallPoint()
@@ -260,6 +271,58 @@ inline bool Foam::wallPoint::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::wallPoint::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const wallPoint& f0,
+    const label i1,
+    const wallPoint& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        if (f1.valid(td))
+        {
+            // What do we do about the origin? Should be consistent with the
+            // distance? But then interpolating between a point 'on the left'
+            // and a point 'on the right' the interpolate might just be on
+            // top of us so suddenly setting the distance to be zero...
+
+            const scalar dist2 =
+                sqr(lerp(sqrt(f0.distSqr()), sqrt(f1.distSqr()), weight));
+
+            if (f0.distSqr() < f1.distSqr())
+            {
+                // Update with interpolated distance and f0 origin
+                return update(f0, dist2, tol, td);
+            }
+            else
+            {
+                return update(f1, dist2, tol, td);
+            }
+        }
+        else
+        {
+            return update(f0, f0.distSqr(), tol, td);
+        }
+    }
+    else if (f1.valid(td))
+    {
+        return update(f1, f1.distSqr(), tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::wallPoint::operator==

src/meshTools/meshStructure/topoDistanceData.H

@@ -196,6 +196,23 @@ public:
                 TrackingData& td
             ) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const topoDistanceData<Type>& f0,
+                const label i1,
+                const topoDistanceData<Type>& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/meshTools/meshStructure/topoDistanceDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -199,6 +199,38 @@ inline bool Foam::topoDistanceData<Type>::equal
 }
 
 
+template<class Type>
+template<class TrackingData>
+inline bool Foam::topoDistanceData<Type>::interpolate
+(
+    const polyMesh&,
+    const point& pt,
+    const label i0,
+    const topoDistanceData<Type>& f0,
+    const label i1,
+    const topoDistanceData<Type>& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    // Topological distance - how to interpolate?
+    if (!valid(td))
+    {
+        if (f0.valid(td))
+        {
+            this->operator=(f0);
+        }
+        else
+        {
+            this->operator=(f1);
+        }
+        return true;
+    }
+    return false;
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 template<class Type>

src/meshTools/regionSplit/minData.H

@@ -174,6 +174,23 @@ public:
             template<class TrackingData>
             inline bool equal(const minData&, TrackingData& td) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const minData& f0,
+                const label i1,
+                const minData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/meshTools/regionSplit/minDataI.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2014-2016 OpenFOAM Foundation
-    Copyright (C) 2015-2020 OpenCFD Ltd.
+    Copyright (C) 2015-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -173,6 +173,35 @@ inline bool Foam::minData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::minData::interpolate
+(
+    const polyMesh& mesh,
+    const point& pt,
+    const label i0,
+    const minData& f0,
+    const label i1,
+    const minData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return updateFace(mesh, -1, f0, tol, td);
+    }
+    if (f1.valid(td))
+    {
+        return updateFace(mesh, -1, f1, tol, td);
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::minData::operator==

src/overset/cellCellStencil/inverseDistance/meshToMeshData.H

@@ -200,6 +200,23 @@ public:
                 TrackingData&
             ) const;
 
+            //- Interpolate between two values (lerp). Returns true if
+            //- causes changes. Not sure if needs to be specialised between
+            //- face and cell and what index is needed...
+            template<class TrackingData>
+            inline bool interpolate
+            (
+                const polyMesh&,
+                const point& pt,
+                const label i0,
+                const meshToMeshData& f0,
+                const label i1,
+                const meshToMeshData& f1,
+                const scalar weight,
+                const scalar tol,
+                TrackingData& td
+            );
+
 
     // Member Operators
 

src/overset/cellCellStencil/inverseDistance/meshToMeshDataI.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2020 OpenCFD Ltd.
+    Copyright (C) 2017-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -205,6 +205,35 @@ inline bool Foam::meshToMeshData::equal
 }
 
 
+template<class TrackingData>
+inline bool Foam::meshToMeshData::interpolate
+(
+    const polyMesh& mesh,
+    const point& pt,
+    const label i0,
+    const meshToMeshData& f0,
+    const label i1,
+    const meshToMeshData& f1,
+    const scalar weight,
+    const scalar tol,
+    TrackingData& td
+)
+{
+    if (f0.valid(td))
+    {
+        return updateFace(mesh, -1, f0, tol, td);
+    }
+    if (f1.valid(td))
+    {
+        return updateFace(mesh, -1, f1, tol, td);;
+    }
+    else
+    {
+        return false;
+    }
+}
+
+
 // * * * * * * * * * * * * * * * Member Operators  * * * * * * * * * * * * * //
 
 inline bool Foam::meshToMeshData::operator==

tutorials/incompressible/pimpleFoam/laminar/mixerVesselAMI2D/mixerVesselAMI2D/system/blockMeshDict.m4

@@ -788,9 +788,14 @@ boundary
 
     AMI1
     {
+        cacheSize       360;
+
         type            cyclicAMI;
         neighbourPatch  AMI2;
         transform       noOrdering;
+        rotationCentre  (0 0 0);
+        rotationAxis    (0 0 1);
+
 /* optional
         surface
         {
@@ -815,9 +820,13 @@ boundary
 
     AMI2
     {
+        cacheSize       360;
+
         type            cyclicAMI;
         neighbourPatch  AMI1;
         transform       noOrdering;
+        rotationCentre  (0 0 0);
+        rotationAxis    (0 0 1);
 /* optional
         surface
         {