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.
This fix changes how the intersections loop ignores previously
intersected faces. It now marks them by their index so that subsequent
iterations ignore them.
Before this change, after an intersection was found the start point was
advanced by a small amount to move the past the intersection. The
problem with this was if multiple boundary faces or the end point were
in close proximity to the intersection then the move forward might span
them. This could lead to intersections being missed or counted multiple
times, in some cases indefinitely.
Based on a patch contributed by Mattijs Janssens
Resolves bug report https://bugs.openfoam.org/view.php?id=1147
- 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()
Helper function to calculate the current face area vs the area returned
from the current point locations. Useful for ACMI-type baffles where we
scale the face areas without moving points.
- 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;
}
- this provides internal consistency and allows direct use of the
coordinate angle with sin(), cos() functions.
It eliminates potential issues that could otherwise arise from
alternative user input.
Eg, in mixerFvMesh it would have previously been possible to specify
the coordinate system to use degrees or radians, but these units were
not checked when determining the tangential sweep positions.
NOTE: this may represent a breaking change if user coding has been
relying on cylindrical coordinate system in degrees.
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
Using: OpenFOAM-plus (see www.OpenFOAM.com)
Build: plus-7ab57cc5d014 (OPENFOAM=1807)
Arch: LSB;label=32;scalar=64
- This can be useful for development versions, or when the version
at build time uses some other naming scheme (#1010)
- 'signed' input parameter only mandatory for distance > 0.
A distance <= 0 is always signed and the input parameter is ignored.
- Use normal distance when distance == 0. This has no effect when
the surface has no open edges, but improves on rounding issues
around the zero crossing when the surface has open edges.
This may still need future revisiting.
- avoid duplicate code by relocating cellZone selection and bounding box
sub-selection into cuttingPlane and cuttingSurfaceBaseSelection.
Allows reuse by inherited classes (sampledPlane, surfMeshSamplePlane).
- takes two general actions:
1. orient edge in canonical direction (positive gradient) and detect
any edge intersection.
2. edge intersection alpha (0-1)
- refactor into a cuttingSurfaceBase intermediate class with the
actions as templated parameters rather than function pointers. This
allows the use of lambda functions with captures from the caller.
- The test condition
[ -n "$cur" -a ... ]
fails if $cur starts with '-le', which bash interprets as a further
test op. Splitting the test condition solves the problem:
[ -n "$cur" ] && [ ... ]
- Since the local edges are oriented according to the gradient,
they can also be used to determine the correct face orientation.
This generalizes the algorithm for future reuse.
