Commit c75d5118 by Mark Olesen

### ENH: improve, simplify, rationalize coordinate system handling (issue #863)

```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.```
parent df995752
 ... ... @@ -31,7 +31,12 @@ coordinates.set ( i, coordinateSystem::New(solidRegions[i], thermos[i]) coordinateSystem::New ( solidRegions[i], thermos[i], coordinateSystem::typeName_() ) ); tmp tkappaByCp = ... ... @@ -57,7 +62,11 @@ ); aniAlphas[i].primitiveFieldRef() = coordinates[i].R().transformVector(tkappaByCp()); coordinates[i].transformPrincipal ( solidRegions[i].cellCentres(), tkappaByCp() ); aniAlphas[i].correctBoundaryConditions(); } ... ...
 ... ... @@ -15,7 +15,12 @@ if (!thermo.isotropic()) const coordinateSystem& coodSys = coordinates[i]; aniAlpha.primitiveFieldRef() = coodSys.R().transformVector(tkappaByCp()); coodSys.transformPrincipal ( mesh.cellCentres(), tkappaByCp() ); aniAlpha.correctBoundaryConditions(); taniAlpha = tmp ... ...
 ... ... @@ -30,12 +30,68 @@ Description \*---------------------------------------------------------------------------*/ #include "argList.H" #include "coordinateSystem.H" #include "Time.H" #include "coordinateSystems.H" #include "identityRotation.H" #include "indirectCS.H" #include "Fstream.H" #include "IOstreams.H" #include "transform.H" using namespace Foam; template void testTransform(const coordinateSystem& cs, const point& p, const T& val) { Info<< " " << pTraits::typeName << ": " << val << " transform: " << cs.transform(p, val) << " invTransform: " << cs.invTransform(p, val) << nl; // Info<< " both: " << cs.invTransform(p, cs.transform(p, val)) << nl; } void basicTests(const coordinateSystem& cs) { cs.writeEntry(cs.name(), Info); if (isA(cs)) { Info<< "indirect from:" << nl; dynamicCast(cs).cs() .writeEntry(cs.name(), Info); } Info<< "rotation: " << cs.R() << nl; List testPoints ({ {1,0,0}, {0,1,0}, {0,0,1}, {1,1,1}, }); for (const point& p : testPoints) { Info<< nl << " test point: " << p << " = local point " << cs.transformPoint(p) << " = local coord " << cs.localPosition(p) << nl; const vector v1(1, 1, 1); const tensor t1(tensor::I); const tensor t2(1, 2, 3, 4, 5, 6, 7, 8, 9); testTransform(cs, p, v1); testTransform(cs, p, t1); testTransform(cs, p, t2); } Info<< nl; } void doTest(const dictionary& dict) { Info<< dict.dictName() << dict << nl; ... ... @@ -43,18 +99,42 @@ void doTest(const dictionary& dict) // Could fail? const bool throwingIOError = FatalIOError.throwExceptions(); const bool throwingError = FatalError.throwExceptions(); try { coordinateSystem cs1(dict.dictName(), dict); auto cs1ptr = coordinateSystem::New(dict, ""); coordinateSystem& cs1 = *cs1ptr; cs1.rename(dict.dictName()); basicTests(cs1); } catch (Foam::IOerror& err) { Info<< "Caught FatalIOError " << err << nl << endl; } catch (Foam::error& err) { Info<< "Caught FatalError " << err << nl << endl; } FatalError.throwExceptions(throwingError); FatalIOError.throwExceptions(throwingIOError); } coordinateSystem cs2; // Move assign cs2 = std::move(cs1); void doTest(const objectRegistry& obr, const dictionary& dict) { Info<< dict.dictName() << dict << nl; // Info<
 /*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v1806 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class IOPtrList; //<-- Older name object coordinateSystems; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ( cs1 { type cartesian; origin (1 2 3); coordinateRotation { type axes; e1 (0 0 1); e2 (0 1 0); } } ) // ************************************************************************* //
 /*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v1806 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object controlDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // application simpleFoam; startFrom latestTime; startTime 0; stopAt endTime; endTime 4; deltaT 1; writeControl timeStep; writeInterval 100; purgeWrite 0; writeFormat binary; writePrecision 6; writeCompression off; timeFormat general; timePrecision 6; runTimeModifiable true; // ************************************************************************* //
 /*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v1806 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; //OLD class IOPtrList; class coordinateSystems; object coordinateSystems; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ( cs1 { type cartesian; origin (1 2 3); rotation { type axes; e1 (0 0 1); e2 (0 1 0); } } cs2 { type cartesian; origin (0 3 5); e1 (1 2 0); e2 (2 0 2); } cs3 { type cartesian; origin (0 3 5); coordinateRotation // older name { type euler; angles (90 0 0); } } cs4 { type cylindrical; origin (0 3 5); rotation { type euler; angles (90 0 0); } } cyl { type cylindrical; origin (0 0 0); degrees false; rotation { type axisAngle; axis (0 0 1); angle 90; } } ident { origin (0 0 0); rotation { type none; } } ) // ************************************************************************* //
 /*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v1806 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object controlDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // application simpleFoam; startFrom latestTime; startTime 0; stopAt endTime; endTime 4; deltaT 1; writeControl timeStep; writeInterval 100; purgeWrite 0; writeFormat binary; writePrecision 6; writeCompression off; timeFormat general; timePrecision 6; runTimeModifiable true; // ************************************************************************* //
 ... ... @@ -10,12 +10,19 @@ FoamFile version 2.0; format ascii; class dictionary; object testDict; object testCsys1; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // // Rotate 90 deg around x: y -> z, z -> -y rot_x90 { origin (0 0 0); e1 (1 0 0); e3 (0 -1 0); } rot_x90_axesRotation { origin (0 0 0); ... ... @@ -27,13 +34,24 @@ rot_x90_axesRotation } } rot_x90_axisAngle { origin (0 0 0); coordinateRotation { type axisAngle; axis (1 0 0); // non-unit also OK angle 90; } } rot_x90_euler { origin (0 0 0); coordinateRotation { type EulerRotation; rotation (0 90 0); // z-x'-z'' type euler; angles (0 90 0); // z-x'-z'' } } ... ... @@ -51,18 +69,40 @@ rot_z45_axesRotation } } rot_z45_axisAngle { origin (0 0 0); coordinateRotation { type axisAngle; axis (0 0 10); // non-unit also OK angle 45; } } rot_z45_euler { origin (0 0 0); coordinateRotation { type EulerRotation; rotation (45 0 0); // z-x'-z'' type euler; angles (45 0 0); // z-x'-z'' } } rot_z45_starcd { origin (0 0 0); coordinateRotation { type starcd; angles (45 0 0); // z-x'-y'' } } // Rotate -45 deg around z: x -> (1 -1 0), y = (1 1 0) rot_zm45_axesRotation { origin (0 0 0); ... ... @@ -74,13 +114,24 @@ rot_zm45_axesRotation } } rot_zm45_axisAngle { origin (0 0 0); coordinateRotation { type axisAngle; axis (0 0 10); // non-unit also OK angle -45; } } rot_zm45_euler { origin (0 0 0); coordinateRotation { type EulerRotation; rotation (-45 0 0); // z-x'-z'' type euler; angles (-45 0 0); // z-x'-z'' } } ... ... @@ -98,13 +149,35 @@ null_axesRotation } } null_axisAngle0 { origin (0 0 0); coordinateRotation { type axisAngle; axis (0 0 0); // non-unit also OK angle 0; } } null_axisAngle1 { origin (0 0 0); coordinateRotation { type axisAngle; axis (1 1 1); // non-unit also OK angle 0; } } null_euler { origin (0 0 0); coordinateRotation { type EulerRotation; rotation (0 0 0); // z-x'-z'' type euler; angles (0 0 0); // z-x'-z'' } } ... ...
 /*--------------------------------*- C++ -*----------------------------------*\