Previously the coordinate system functionality was split between
coordinateSystem and coordinateRotation. The coordinateRotation stored
the rotation tensor and handled all tensor transformations.
The functionality has now been revised and consolidated into the
coordinateSystem classes. The sole purpose of coordinateRotation
is now just to provide a selectable mechanism of how to define the
rotation tensor (eg, axis-angle, euler angles, local axes) for user
input, but after providing the appropriate rotation tensor it has
no further influence on the transformations.
--
The coordinateSystem class now contains an origin and a base rotation
tensor directly and various transformation methods.
- The origin represents the "shift" for a local coordinate system.
- The base rotation tensor represents the "tilt" or orientation
of the local coordinate system in general (eg, for mapping
positions), but may require position-dependent tensors when
transforming vectors and tensors.
For some coordinate systems (currently the cylindrical coordinate system),
the rotation tensor required for rotating a vector or tensor is
position-dependent.
The new coordinateSystem and its derivates (cartesian, cylindrical,
indirect) now provide a uniform() method to define if the rotation
tensor is position dependent/independent.
The coordinateSystem transform and invTransform methods are now
available in two-parameter forms for obtaining position-dependent
rotation tensors. Eg,
... = cs.transform(globalPt, someVector);
In some cases it can be useful to use query uniform() to avoid
storage of redundant values.
if (cs.uniform())
{
vector xx = cs.transform(someVector);
}
else
{
List<vector> xx = cs.transform(manyPoints, someVector);
}
Support transform/invTransform for common data types:
(scalar, vector, sphericalTensor, symmTensor, tensor).
====================
Breaking Changes
====================
- These changes to coordinate systems and rotations may represent
a breaking change for existing user coding.
- Relocating the rotation tensor into coordinateSystem itself means
that the coordinate system 'R()' method now returns the rotation
directly instead of the coordinateRotation. The method name 'R()'
was chosen for consistency with other low-level entities (eg,
quaternion).
The following changes will be needed in coding:
Old: tensor rot = cs.R().R();
New: tensor rot = cs.R();
Old: cs.R().transform(...);
New: cs.transform(...);
Accessing the runTime selectable coordinateRotation
has moved to the rotation() method:
Old: Info<< "Rotation input: " << cs.R() << nl;
New: Info<< "Rotation input: " << cs.rotation() << nl;
- Naming consistency changes may also cause code to break.
Old: transformVector()
New: transformPrincipal()
The old method name transformTensor() now simply becomes transform().
====================
New methods
====================
For operations requiring caching of the coordinate rotations, the
'R()' method can be used with multiple input points:
tensorField rots(cs.R(somePoints));
and later
Foam::transformList(rots, someVectors);
The rotation() method can also be used to change the rotation tensor
via a new coordinateRotation definition (issue #879).
The new methods transformPoint/invTransformPoint provide
transformations with an origin offset using Cartesian for both local
and global points. These can be used to determine the local position
based on the origin/rotation without interpreting it as a r-theta-z
value, for example.
================
Input format
================
- Streamline dictionary input requirements
* The default type is cartesian.
* The default rotation type is the commonly used axes rotation
specification (with e1/e2/3), which is assumed if the 'rotation'
sub-dictionary does not exist.
Example,
Compact specification:
coordinateSystem
{
origin (0 0 0);
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
Full specification (also accepts the longer 'coordinateRotation'
sub-dictionary name):
coordinateSystem
{
type cartesian;
origin (0 0 0);
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
}
This simplifies the input for many cases.
- Additional rotation specification 'none' (an identity rotation):
coordinateSystem
{
origin (0 0 0);
rotation { type none; }
}
- Additional rotation specification 'axisAngle', which is similar
to the -rotate-angle option for transforming points (issue #660).
For some cases this can be more intuitive.
For example,
rotation
{
type axisAngle;
axis (0 1 0);
angle 30;
}
vs.
rotation
{
type axes;
e2 (0 1 0);
e3 (0.5 0 0.866025);
}
- shorter names (or older longer names) for the coordinate rotation
specification.
euler EulerRotation
starcd STARCDRotation
axes axesRotation
================
Coding Style
================
- use Foam::coordSystem namespace for categories of coordinate systems
(cartesian, cylindrical, indirect). This reduces potential name
clashes and makes a clearer declaration. Eg,
coordSystem::cartesian csys_;
The older names (eg, cartesianCS, etc) remain available via typedefs.
- added coordinateRotations namespace for better organization and
reduce potential name clashes.
- Can now retrieve or set a column/row of a tensor.
Either compile-time or run-time checks.
Get
t.col<1>(); t.col(1);
t.row<1>(); t.row(1);
Set
t.col<1>(vec); t.col(1,vec);
t.row<1>(vec); t.row(1,vec);
The templated versions are compile-time checked
t.col<3>();
t.col<3>(vec);
The parameter versions are run-time checked
t.col(3);
t.col(3,vec);
ENH: provide named access to tensor/tensor inner product as inner()
- nBoundaryFaces() is often used and is identical to
(nFaces() - nInternalFaces()).
- forward the mesh nInternalFaces() and nBoundaryFaces() to
polyBoundaryMesh as nFaces() and start() respectively,
for use when operating on a polyBoundaryMesh.
STYLE:
- use identity() function with starting offset when creating boundary maps.
labelList map
(
identity(mesh.nBoundaryFaces(), mesh.nInternalFaces())
);
vs.
labelList map(mesh.nBoundaryFaces());
forAll(map, i)
{
map[i] = mesh.nInternalFaces() + i;
}
Previously had 3 possibilities for handling exposed internal faces
1. use default "oldInternalFaces"
2. specify -patch, to use the specified (existing) patch
3. specify -patches, to use the geometrically closest patches
Now relaxed the restriction on -patch to allow specification of a new
(not yet existing) patch name. This improves flexibility, but won't
catch typing mistakes.
Harmonize behaviour of -patches and -patch. When -patches is used to
specify a single, non-regex patch name, it now behaves identically to
-patch. Since the getList handling for options already allows special
treatment for single parameter lists, the following will work
identically:
subsetMesh -patch patch0
subsetMesh -patches patch0
subsetMesh -patches '( patch0 )'
In the future it might be reasonable to fully combine the behaviour of
'-patch' and '-patches' and treat them as aliases for each other.
ENH: support subsetMesh on a cellZone.
- when the '-zone' option is specified, the command argument is treated
as the name (or names) of cellZones to be selected instead of as the
name of the cellSet.
The command argument can be a single word, regex, or list of
word/regex.
Eg,
subsetMesh -zone -patch mypatch mixer
subsetMesh -zone -patch mypatch '(mixer "moving.*" )'
STYLE: simplify set handling and other code cleanup in subsetMesh
- there were previously no hashing mechanisms for lists so they
would fall back to the definition for primitives and hash the
memory location of the allocated List object.
- provide a UList::Hash<> sub-class for inheritance, and also a global
specialization for UList<T>, List<T> such that the hash value for
List<List<T>> cascades properly.
- provide similar function in triFace to ensure that it remains
similar in behaviour to face.
- added SymmHash to Pair, for use when order is unimportant.
STYLE: use string::hash() more consistently
- no particular reason to use Hash<word>() which forwards to
string::hash() anyhow
- With argList::noFunctionObjects() we use the logic added in
4b93333292 (issue #352)
By removing the '-noFunctionObjects' option, we automatically
suppress the creation of function-objects via Time (with argList
as a parameter).
There is generally no need in these cases for an additional
runTime.functionObjects().off() statement
Use the argList::noFunctionObjects() for more direct configuration
and reduce unnecessary clutter in the -help information.
In previous versions, the -noFunctionObjects would have been redundant
anyhow, so we can also just ignore it now instead.
- allows use with any container with begin(), end() and where the
"*iterator" dereference returns a label, which is used for indexing
into the list of points.
This container could be labelUList, bitSet, labelHashSet, etc
- signedDistance() method is like distance() but retains
the positive/negative sign for the side of the plane.
- the sign() method returns the sign as -1,0,+1 integer for
classification purposes where it is important to distinguish between
a zero value and a positive value (eg, for cutting). Optional
tolerance can be supplied to round for zero.
- refactor and inlined simple and frequently used methods.
- add boundBox faceCentre() method, which can be useful for creating
clipping planes from a bounding box.
Relocated treeBoundBox faceNormals to boundBox since they apply
equally there - the meaning of the faces (x-min, x-max, etc)
is the same, even if the point addressing for the faces differs.
- rationalized code dealing with extraction of name or indices from
coordinateSystems, polyBoundaryMesh, faBoundaryMesh, fvBoundaryMesh,
ZoneMesh to use internal implementations that allow direct
searching/matching without building an intermediate list of names.
- simpler and more efficient handling of patch group matching.
- centralizes IOobject handling and treatment of alternative locations.
If an alternative file location is specified, it will be used instead.
- provide decompositionMethod::canonicalName instead of using
"decomposeParDict" in various places.
- allows for simpler unpacking of a full list, or list range into any
sufficiently large integral type.
For example,
processorPolyPatch pp = ...;
UOPstream toNbr(pp.neighbProcNo(), pBufs);
toNbr << faceValues.unpack<char>(pp.range());
