View Issue Details

IDProjectCategoryView StatusLast Update
0032462CommunityOCCT:Meshpublic2023-08-01 15:08
Reportergstamm Assigned Tooan  
Status newResolutionopen 
PlatformWindows 10OSWindows 10 
Product Version7.4.0 
Target VersionUnscheduled 
Summary0032462: Mesh - missing face issue, bad surface and bad volume [Regression compared to OCCT 7.3.0]
DescriptionHello dear community,

I'm facing an issue with the kernel of OCC.

To illustrate my issue I'm using CAD Assistant in the snapshots, but same regression could be observed with FreeCAD, PythonOCC...

If you open the attached STEP file in two version of CAD Assistant, in the more recent version, one face is missing, and then on this part volume and surface computation are KO.

cad_assistant_1.5.0_2020-12-28_win64 : version used for KO snapshot
cad_assistant_1.2_2018-10-30_win64 : version used for OK snapshot.

Do you have an idea on how to treat this part with the last versions of the kernel?

Healing of the step file?

Bug in the kernel?

Thanks for your attention,

Best regards

Guillaume STAMM
Steps To Reproduce
restore vol_731dev.brep b
#testreadstep volume_ko.stp b
tclean b
checkshape b b

incmesh b 1.0

vinit View1
vdisplay -dispMode 1 b

# KO
> -- The Shape b looks OK
> Meshing statuses: SelfIntersectingWire Failure

TagsNo tags attached.
Test case number

Attached Files

  • issue 3d and (369,257 bytes)
  • vol_731dev.brep (566,317 bytes)


related to 0025061 newoan Open CASCADE BRepMesh should skip internal wires with self intersections to produce mesh for the shape anyway 
related to 0024084 assignedoan Open CASCADE Additional tool for resolving 2d loops on discretized wires should be implemented in BRepMesh 
child of 0026106 closedbugmaster Open CASCADE BRepMesh - revision of data model 



2021-06-27 01:34


issue 3d and (369,257 bytes)


2021-06-28 15:13


vol_731dev.brep (566,317 bytes)


2021-06-28 15:19

developer   ~0102119

> in the more recent version, one face is missing
Face is not missing, it is still there, but triangulation algorithm fails on it due to wire self-intersection error.

This is either a problem in Face definition, or BRepMesh classifier issue.

Issue History

Date Modified Username Field Change
2021-06-27 01:34 gstamm New Issue
2021-06-27 01:34 gstamm Assigned To => abv
2021-06-27 01:34 gstamm File Added: issue 3d and
2021-06-28 15:13 kgv File Added: vol_731dev.brep
2021-06-28 15:19 kgv Note Added: 0102119
2021-06-28 15:19 kgv Product Version 7.5.1 => 7.4.0
2021-06-28 15:19 kgv Target Version => 7.6.0
2021-06-28 15:19 kgv Steps to Reproduce Updated
2021-06-28 15:20 kgv Assigned To abv => oan
2021-06-28 15:20 kgv Severity major => minor
2021-06-28 15:20 kgv Category OCCT:Foundation Classes => OCCT:Mesh
2021-06-28 15:20 kgv Summary Regression on OCC: missing face issue, bad surface and bad volume => Mesh - missing face issue, bad surface and bad volume [Regression compared to OCCT 7.3.0]
2021-06-28 15:22 kgv Relationship added child of 0026106
2021-06-28 15:22 kgv Relationship added related to 0025061
2021-06-29 11:42 oan Relationship added related to 0024084
2021-11-01 18:13 szy Target Version 7.6.0 => 7.7.0
2022-10-24 10:40 szy Target Version 7.7.0 => 7.8.0
2023-08-01 15:08 dpasukhi Target Version 7.8.0 => Unscheduled