The root of the problem is incorrect processing of cases when intersection line goes through the apex(es) of sphere. The fix improves this situation. The algorithm is taken from DecomposeResult(...) function (see IntPatch_ImpPrmIntersection.cxx file). Before the fix, faltering steps were done to solve this problem. As result, it worked in some particular cases. Now, its possibilities have been extended significantly.
Following changes have been made in the fix:
1. Class IntPatch_ALineToWLine has been rewritten cardinally. It touches as interfaces of existing methods as adding/removing some methods/fields. Correction touches both cases: going through seam of Cone/Sphere and through pole(s) of sphere. Old interface did not allow making some actions with analytical line (ALine), e.g. splitting it on several Walking-lines (WLine).
2. Restriction-line support has been removed from Implicit-Implicit intersection result (see IntPatch_Intersection::GeomGeomPerfom(...) method). It connects with the fact that the intersection algorithm itself returns precise intersection line in analytical cases (in compare with parametric intersector). Therefore, we do not need in additional (restriction) line.
3. New class IntPatch_SpecialPoints has been added. This class contains methods to add some special points (such as apex of cone, pole of sphere, point on surface boundary etc.) in intersection line (IntPatch_PointLine). It is based on the static functions, which already exist in IntPatch_ImpPrmIntersection.cxx file (these functions have been moved to the new class).
4. Method IntPatch_WLineTool::ExtendTwoWlinesToEachOther(...) has been renamed to IntPatch_WLineTool::ExtendTwoWLines(...). It is connected with changing main idea of the method. Now it allows extending WLine to the surface boundary or to the singular point (if it is possible): cone apex, sphere pole etc. Interface of this method has been corrected, too. At that, old functionality (extending to each other) has been kept. For implementation of this algorithm, new enumeration "IntPatchWT_WLsConnectionType" has been created.
5. Method IntPatch_PointLine::CurvatureRadiusOfIntersLine(...) has been added. See IntPatch_PointLine.hxx for detail information. It allows correct step computing depended on the local curvature of the intersection line. This method uses geometrical properties of intersected surfaces to compute local curvature. Therefore, it can be applied in wide range of cases even if the intersection curve is not represented in explicit form (e.g. in case of param-param-intersection).
6. Method IntSurf::SetPeriod(...) has been created.
7. Additional check has been added in Draft_Modification::Perform() method for better choice of correct fragment of intersection line for processing DRAFT operation.
8. New overload method IntPatch_Point::SetValue() has been added.
9. Some refactoring of the code has been made.
Creation of test case for issue #27431.
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Some test cases have been adjusted according to their new behavior.
tests\bugs\modalg_4\bug62
It is really IMPROVEMENT (but fortuitous).
tests\bugs\modalg_5\bug25838
The behavior of this test has been reverted to the state before fixing the issue #27341. Main problem has not been fixed in #27341. It was fortuitous improvement.
tests\bugs\moddata_2\bug565
Quality of intersection curve was not checked. And the curve is bad on both MASTER and FIX. Input data are really wrong: plane-like-cone. However, on the MASTER, four intersection curves (the quality is insignificant) are expected. On the fix, not empty intersection result is expected simply.
tests\boolean\volumemaker\A8
Differences in images and CPU is expected. Difference in images is expected to be fixed in the issue #26020. Now, we should apply this behavior.
Much CPU time is spent by IntTools_FaceFace::ComputeTolReached3d(...) and GeomInt_IntSS::BuildPCurves(...) methods calling. These methods are not touched by the algorithm. It is the result of change of intersection curve(s) form. However, the new Curve(s) seems to be valid and can be applied. As result, new behavior can be applied, too.
tests\boolean\volumemaker\F8
tests\boolean\volumemaker\F9
tests\boolean\volumemaker\G5
tests\boolean\volumemaker\G6
CPU difference is expected. Much CPU time is spent by IntPatch_PointLine::CurvatureRadiusOfIntersLine(...) method calling. This method is really new (it does not exist on the MASTER) and is really useful. Therefore, we should apply new behavior.
tests\boolean\volumemaker\G1
CPU difference is expected. Much CPU time is spent by IntTools_WLineTool::DecompositionOfWLine(...) and IntTools_FaceFace::ComputeTolReached3d(...) methods calling. These methods are not touched by the algorithm. It is the result of change of intersection curve(s) form. However, the new Curve(s) seems to be valid and can be applied. As result, new behavior can be applied, too.
tests\bugs\modalg_6\bug26619
Differences in images is expected. The test keeps its BAD status on the FIX. But the result on the fix is nearer to expected than on the MASTER. Issue #27014 is still actual. As before, it is not clear, why the number of entities is different. The number of section curves has not been changed. Interfered entities are the same as on the MASTER.
tests\bugs\modalg_5\bug25319_1(2)
The reason is described in the issue #27896.
Small correction in the test case
In ProjLib_ComputeApprox algorithm, compute correct parametric tolerance from the input 3D tolerance using surface resolution, in order to pass it to low-level 2D algorithm Approx_FitAndDivide2d (instantiation of the generic class Approx_ComputeCLine). Earlier 3D tolerance was used as parametric tolerance directly, which was a problem for surfaces with too small radius of curvature.
Also, eliminate redundant creation of the object of type AppParCurves_MultiCurve on each iteration in the method Approx_ComputeCLine::Compute.
The post treatment of the Edge/Edge intersections has been improved. Namely:
a. Making the procedure of sharing Edge/Edge intersection vertices consistent with intersection algorithm by enlarging bounding box of each vertex on half of Precision::Confusion();
b. Algorithm of computation of vertex tolerance (in order to cover tangent zone between Edges) has been changed for Line/Circle cases.
Test cases for issue CR27804
Adjusting test cases according to their new behavior.
Mark the test boolean/volumemaker/A8 as unstable between different versions of MSVS (2010 and 2013).
- Ensure that the subshapes from the original shape will not be changed after nurbsconvert operation.
For that create the new vertexes (NewPoint(..)) as well as new curves (NewCurve(..)) and new surfaces (NewSurface(..)) before calling of Rebuild() method. Make copies of all vertexes impacted by curve or surface modifications. This eliminates necessity of creation of new vertices during recursive rebuilding of the entire shape.
- Compatibility with the old behavior of BRepTools_Modifier has been retained as an option. For that the new flag MutableInput has been added in the interface of the class.
- This patch also impacts other operations based on BRepTools_Modifier, in the sense that they also become safe regarding input shapes.
- Create new test cases. Some test cases with nurbsconvert command are changed to lock input shapes from modifications.
fix regressions
1) BRepMesh_FastDiscretFace.cxx:
- exclude planes from procedure of inserting internal points.
- localize declaration of the container aNewVertices in each method where it is needed.
- correct the logic of the method insertInternalVerticesOther, so that to separate the processes of removing extra points and addition of new points in different cycles, thus making the code more clear and in addition stable.
- insert useful output of intermediate mesh to a file in control() method for debug purposes (with definition DEBUG_MESH).
2) Add global functions MeshTest_DrawTriangles and MeshTest_DrawLinks to draw mesh data in debug session.
3) BRepMesh_FastDiscret:
- in the method Add calculations of deflections have been simplified for non-relative mode.
- replace the attribute MinDist with Deflection in EdgeAttributes structure. Correct its computation so that later to store this value as deflection of the polygon.
4) Make protection against exception in the method BRepMesh_Delaun::addTriangle() when an added triangle creates a third connection of a mesh edge.
5) BRepMesh_EdgeTessellator.cxx, BRepMesh_EdgeTessellationExtractor.cxx: use Geom2dAdaptor_Curve in order to use b-spline cache while computing value on a curve.
6) In BndLib_Box2dCurve::PerformBSpline, avoid creating new b-spline in case of requested parameter range differ from natural bounds insignificantly.
7) In GeomAdaptor classes, postpone building of cache till the time of its actual usage. So, creation of an adapter to compute intervals of continuity does not lead to creation of internal cache.
8) In the methods BRepAdaptor_Curve::Bezier and BSpline do not call Transformed() if transformation is identity.
9) In the classes Geom_BSplineCurve, Geom_BSplineSurface, Geom_BezierCurve, Geom_BezierSurface, Geom2d_BSplineCurve, Geom2d_BezierCurve change the method Pole() to return the point by const reference.
10) In CPnts_AbscissaPoint.cxx, compute derivative by D1 instead of DN to make use of b-spline cache.
11) Change test cases to actual state:
- Number of triangles/nodes can grow due to more accurate work with deflection of edges. Now the edge is tessellated using its own tolerance instead of maximal tolerance of all shapes in the face.
- Accept new numbers of mesh errors (free links, free nodes) for really bad shapes.
- Correct the test "bugs/mesh/bug25612" to produce stable result.
- Disable redundant checks in test cases bug25378* (lower limit for computation time).
- Speed up iso-lines computation for offset of bspline surfaces. For that use adaptor instead of original surface in evaluator of approximation.
- Add output of polylines for debug of insertInternalVerticesOther().
Reference data in test case bugs\moddata_2\bug453_3 have been changed to be close to expected theoretical values. This makes the test give stable result on different platforms.
Modification of algorithm in order to prevent violation of angular and curvature deflection condition for smooth intervals of curve.
Modification of algorithm for calculation of maximal deflection in command crvtpoints, crvpoints (CR25649)
Elementary bug fixing in algorithm GCPnts_UniformDeflection.gxx
Modification of test cases in order to set new reference parameters of shape triangulations
Some tests:
bugs modalg_2 bug397
mesh standard_incmesh C7, V3
mesh standard_incmesh_parallel C7, V3
mesh standard_mesh C7, V3
mesh standard_shading V3
were modified by TODO with reference bug 27226, because some problems in meshing algorithm (package BRepMesh) were discovered when tessellation of edges was changed. These problems cannot be solved by modification of GCPnts_TangentialDeflection algorithm. New issue #27226 was created, see bugtracker for details.
Correction of test data
Test case for issue #27108
Modification of algorithm for improving performance
Correction of test cases
Euclidean distance criteria is added for local point / surface extrema.
Classes representing objective criteria are renamed to be consistent.
Local extrema usage is updated according to new behavior.
Test case is added.
Misprint correction.
Check deviation of normals at vertices of triangles for complex surface types different from Bezier and BSpline.
Modified test cased according to changes in BRepMesh.
Do not remove more intermediate parameters than N - 3 in order to have at least one parameter related to surface internals.
Check angle for angular deflection before removement of intermediate parameters.
Unify computation of internal vertices for complex surfaces.
Discretization points of edges are taken into account during computation of step of mesh grid.
Remove parameters only if they fit the constrains along the whole surface.
Do not add random internal parameters in case if their number is just 2.
Force freezing parameters both for U and V in case of significant control point.
Modified test cases
Warnings elimination in vc14.
Command checkplatform was created.
All test cases were updated.
Global variable os_type was eliminated.
New option -osx (MacOS) for procedure checkplatform was added.
Topological tolerances changed to geometric tolerances.
Protection from the usage of invalid result is added to restore good projection.
Test cases are updated.
Test case added.
Correction of test case for issue CR27133
Possibility to read shapes and OCAF documents from old persistence format (Std and StdL schema) is restored.
Test cases used old persistent files on input are restored with suffix "_std"
Removing toolkit from OS package
Extrema Curve / Surface algorithm changed to perform more accurate search.
test case bug25232_8 - improvement, one additional intersection point is detected now.
test case bug23830 - normal behavior, position of extrema is changed.
test case for original issue added.
1. Disable recalculation of B-spline cache when the parameter is out of surface boundary but near the cached span.
2. Rebuild cache each time a curve/surface is loaded into adaptor (B-spline knots may be re-parametrized outside adaptor without changing base curve)
3. Test cases.
- Added function checkprops, set default tolerance parameter to 1.0e-4
- Using "area" instead of "square".
- Options "-equal\notequal" isn't used together with "-s" in blend and offset test cases.
- Correct regressions/differences/improvements and CPU problem (set props tolerance to 0.1)
- Corrected test cases to use checkprops proc.
- Correct image difference
- Updated TODOs in test cases.
- Updated test cases to get correct images of result shape
Check, if cylinder axes are parallel is made more carefully.
This check is brought to conformity with check if axes are parallel (see constructor AxeOperator::AxeOperator(...) in IntAna_QuadQuadGeo.cxx file)
Test case for issue CR26884
Added possibility to define patterns that must be present in the test log, so that test is considered OK only if all these patterns are found.
New REQUIRED statement is introduced for that, documented in dox/dev_guides/tests/tests.md.
Removed all uses of decho and dlog commands, added REQUIRED where necessary.
Command xdistcs is modified to output to Tcl instead of cout, and extended to report errors and warnings if distances are greater than tolerance (directly, instead of complex post-processing on Tcl level).
DEBUG mode for TODOs was removed (we should have no deviations in Debug mode).
Corrected indentation in DrawResources/TestCommands.tcl
HTML log will now highlight TODO statement causing IMPROVEMENT status, or REQUIRED statement causing FAIL, by corresponding color.
Poles bounding box for curve added for bezier and bspline curves.
Method Poles() for Bezier curve added.
Test case for issue CR26560
Function to compute subshape max tolerance has been added.
Fixed bounding box expanding at Face/Face step of boolean operation.
Test cases are updated to the new behavior.
Changed the rules for the types of the arguments for different operations:
1. FUSE: All arguments and tools should have the same dimension;
2. CUT: The MAXIMAL dimension of the ARGUMENTS should be less
or equal to the MINIMAL dimension of the TOOLS;
3. CUT21: The MINIMAL dimension of ARGUMENTS should be grater
or equal to the MAXIMAL dimension of the TOOLS;
4. COMMON: The arguments and tools could have any dimensions.
For the arguments of collection type (WIRE, SHELL, COMPSOLID)
the type will be passed into the result of the operation.
The documentation should be updated according to new behavior.
Documentation has been updated.
Implemented suggestions by MSV and some grammar changes.
Test cases for issue CR26565
Correction of test cases for issue CR26565
Correction of test cases for issue CR26565
Removed check for C0 surface while copying offset surface
General code melioration
Test case for issue CR26522
Ignoring C0 basis surface while reading offset surface (added)
C2 continuity intervals changed to Knots intervals in case of Bspline curve.
Fixed incorrect extremaPC usage.
Test case for issue CR26351
Update of test-cases according to the new behavior
Changed computation of point projection to more correct.
Calculation periodicity information added to cache.
Test case for issue CR26339
Small correction of test case for issue CR26339
1. B-spline cache was moved into separated classes: BSplCLib_Cache for 2D and 3D curves and BSplSLib_Cache for surfaces.
2. The cache is used now in corresponding adaptor classes (Geom2dAdaptor_Curve, GeomAdaptor_Curve and GeomAdaptor_Surface) when the curve or surface is a B-spline.
3. Algorithms were changed to use adaptors for B-spline calculations instead of curves or surfaces.
4. Precised calculation of derivatives of surface of revolution is implemented for the points of surface placed on the axis of revolution (Geom_SurfaceOfRevolution.cxx)
5. Small modifications are made to adjust algorithms to new behavior of B-spline calculation.
6. Test cases were modified according to the modern behavior.
7. Changes in BOPAlgo_WireSplitter, BOPTools_AlgoTools, BRepLib_CheckCurveOnSurface and ShapeAnalysis_Wire to use adaptors instead of geometric entities
8. Allow Geom2dAdaptor and GeomAdaptor in case of offset curve to use corresponding adaptor for basis curve
Modification of test-cases according to the new behavior.
All uses of "MDTV-Standard" and "MDTV-Design" in tests changed to "BinOcaf", and "MDTV-XCAF" changed to "BinXCAF".
Formats changed: .std to .cbf, .dxc to .dbf.
Test groups renamed accordingly:
xcaf: brep_to_dxc -> brep_to_xbf, igs_to_dxc -> igs_to_xbf, stp_to_dxc -> stp_to_xbf, dxc -> xbf/A1, dxc_add_CL -> xbf_add_CL
xml: ocaf_std -> ocaf_cbf, xcaf_dxc -> xcaf_xbf
1. Function IntImp_Int2S::ChangePoint() has been added (see cdl for detail information).
2. Attempt to forbidden break WLine if it goes along surface boundary.
Code optimization.
2nd optimization
Test case for issue CR25890
Precision used to consider B-Spline knots identical is restricted to be not less than Precision::PConfusion() in Geom2d_BSplineCurve::Segment().
Affected tests updated (improvements)
Test case for issue CR25971
Test for sewing command were updated to check reference information.
Commands for testing were moved to the file src/DrawResources/CheckCommands.tcl
Documentation overview was updated.
Unstable test cases were reviewed
Modified test cases using checktrend command
Modified test cases for Linux platform
Modified test cases for Debug mode