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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0033234||Community||OCCT:Shape Healing||public||2022-11-29 22:21||2023-09-29 18:07|
|Summary||0033234: BRepMesh_IncrementalMesh does not fully triangulate some surfaces|
|Description||When meshing with BRepMesh_IncrementalMesh some surfaces are not triangulated or partially triangulated.|
The results are better when using IMeshTools_MeshAlgoType_Delabella, but there are still some holes.
The issue is present in OCCT v7.6.3 and 7.7.0. Screenshots are made with linear deflection = 1, relative = false, angular deflection = 0.1.
Its a regression as there is no issue in OCCT v7.2.0.
|Tags||No tags attached.|
|Test case number|
image.png (393,875 bytes)
delabella.png (133,680 bytes)
the shape contains some issues that cause triangulation look bad.
checkshape reports the following problems:
On Shape faulty_1 : BRepCheck_SelfIntersectingWire On Shape faulty_2 : BRepCheck_UnorientableShape Shape faulty_1 on shape faulty_2 : BRepCheck_SelfIntersectingWire On Shape faulty_3 : BRepCheck_SelfIntersectingWire On Shape faulty_4 : BRepCheck_UnorientableShape Shape faulty_3 on shape faulty_4 : BRepCheck_SelfIntersectingWire Faulty shapes in variables faulty_1 to faulty_4
Note that the issues reported either by checkshape or bopargcheck notify user about general problems that could cause further degeneracy in any algorithm, BRepMesh is not an exception.
All these problems say that design in imperfect and should be fixed either manually, or using fixshape.
Using fixshape like this:
stepread Swirler.step a * fixshape r a_1 +i
Gives the result pictured on the attached screenshot.
Despite of nice looking result, there are some problems anyway:
tricheck reports free nodes, which is practically thin holes along border of just some skipped nodes from initial discretization.
Moreover, checkshape also says about the same problems reported before healing procedure.
Like this, current issue is just a visual representation of hidden design problems existing in its parts and should be qualified as related to Shape Healing component.
Swirler.png (75,416 bytes)
by the way, it seems that the shape is the result of some sweep operation or so.
It would be nice if you added the source shapes or script that are used to produce the problematic solid (the one you have already attached) in order to analyze the cause of the problems mentioned in the previous message.
Swirler.zip.001 (2,097,152 bytes)
Swirler.zip.002 (2,097,152 bytes)
Swirler.zip.003 (2,097,152 bytes)
Swirler.zip.004 (2,097,152 bytes)
Swirler.zip.005 (1,229,918 bytes)
||The shape was generated in SolidWorks and exported to STEP.|
|2022-11-29 22:21||bogdan_138692||New Issue|
|2022-11-29 22:21||bogdan_138692||Assigned To||=> oan|
|2022-11-29 22:23||bogdan_138692||Note Added: 0112408|
|2022-11-29 22:23||bogdan_138692||File Added: image.png|
|2022-11-29 22:23||bogdan_138692||File Added: delabella.png|
|2022-11-30 21:55||oan||Relationship added||duplicate of 0033233|
|2022-11-30 22:17||oan||Note Added: 0112434|
|2022-11-30 22:17||oan||File Added: Swirler.png|
|2022-11-30 22:18||oan||Note Edited: 0112434|
|2022-11-30 22:19||oan||Note Edited: 0112434|
|2022-11-30 22:24||oan||Note Added: 0112435|
|2022-11-30 22:30||oan||Note Added: 0112436|
|2022-11-30 22:30||oan||File Added: Swirler.zip.001|
|2022-11-30 22:30||oan||Note Added: 0112437|
|2022-11-30 22:30||oan||File Added: Swirler.zip.002|
|2022-11-30 22:30||oan||Note Added: 0112438|
|2022-11-30 22:30||oan||File Added: Swirler.zip.003|
|2022-11-30 22:30||oan||Note Added: 0112439|
|2022-11-30 22:30||oan||File Added: Swirler.zip.004|
|2022-11-30 22:30||oan||Note Added: 0112440|
|2022-11-30 22:30||oan||File Added: Swirler.zip.005|
|2022-12-01 14:56||oan||Assigned To||oan => ika|
|2022-12-01 14:56||oan||Category||OCCT:Mesh => OCCT:Shape Healing|
|2022-12-01 19:52||bogdan_138692||Note Added: 0112457|
||Status||new => assigned|
|2023-09-29 18:07||ika||Assigned To||ika =>|
|2023-09-29 18:07||ika||Target Version||=> Unscheduled|