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0026928Community[OCCT] OCCT:Meshpublic2015-11-25 15:272018-11-11 12:01
Markus 
bugmaster 
normalminor 
closedfixed 
[OCCT] 6.9.1 
[OCCT] 7.4.0[OCCT] 7.4.0 
bugs mesh bug26928
0026928: Edges are meshed too coarsly
In the appended case, the edges seem to be discretized too coarsly by BRepMesh_IncrementalMesh. It is especially visible because the corresponding surface, which is created from the edges by ThruSections is meshed much finer.

If you meassure the distance between the curve and its tessellation, it seems to be bigger than the linear deflection.
bugs moddata_3 bug27356


#manual steps
restore comp.brep c

vinit

vdisplay c

vfit

vsetdispmode c 1

# These are the Parameters the shape was originally meshed with => no Change
incmesh c 0.715 -a 11.459

vdisplay -redisplay c

incmesh c 0.5 -a 11.459

vdisplay -redisplay c

incmesh c 0.3 -a 11.459

vdisplay -redisplay c

incmesh c 0.1 -a 11.459

vdisplay -redisplay c
# only here the curve looks better
No tags attached.
related to 0026532closed bugmaster Community Meshing of edge with minSize parameter leads to incorrect result 
child of 0027356closed bugmaster Open CASCADE BRepTools::Clean() does not clean free edges from Poly_Polygon3D 
? comp.brep (73,602) 2015-11-25 15:27
https://tracker.dev.opencascade.org/
png too coarse edges.png (16,840) 2015-11-25 15:28
https://tracker.dev.opencascade.org/
Issue History
2015-11-25 15:27TimoNew Issue
2015-11-25 15:27TimoAssigned To => oan
2015-11-25 15:27TimoFile Added: comp.brep
2015-11-25 15:28TimoFile Added: too coarse edges.png
2015-11-25 15:29TimoRelationship addedrelated to 0026532
2015-11-25 15:38TimoNote Added: 0048569
2015-12-18 11:50abvTarget Version7.0.0 => 7.1.0
2016-04-05 17:04oanRelationship addedchild of 0027356
2016-04-05 17:14oanNote Added: 0052404
2016-04-15 18:17oanSteps to Reproduce Updatedbug_revision_view_page.php?rev_id=13497#r13497
2016-11-03 17:21abvTarget Version7.1.0 => 7.2.0
2017-05-31 15:38TimoReporterTimo => Markus
2017-07-20 12:43oanTarget Version7.2.0 => 7.3.0
2017-08-15 18:55mkvTest case number => bugs mesh bug26928
2017-08-15 18:55mkvNote Added: 0069421
2018-02-08 22:40abvTarget Version7.3.0 => 7.4.0
2018-11-02 18:30oanNote Added: 0080659
2018-11-02 18:30oanAssigned Tooan => bugmaster
2018-11-02 18:30oanStatusnew => feedback
2018-11-07 15:53nbvAssigned Tobugmaster => oan
2018-11-07 15:53nbvNote Added: 0080835
2018-11-07 16:24oanNote Added: 0080847
2018-11-07 16:25oanAssigned Tooan => nbv
2018-11-07 16:33nbvSteps to Reproduce Updatedbug_revision_view_page.php?rev_id=20341#r20341
2018-11-07 16:57nbvNote Added: 0080848
2018-11-07 17:00gitNote Added: 0080851
2018-11-07 17:27gitNote Added: 0080873
2018-11-07 17:54gitNote Added: 0080881
2018-11-07 18:15gitNote Added: 0080898
2018-11-07 18:16nbvNote Added: 0080899
2018-11-07 18:16nbvAssigned Tonbv => msv
2018-11-07 18:16nbvStatusfeedback => resolved
2018-11-08 11:40msvNote Added: 0080926
2018-11-08 11:40msvAssigned Tomsv => nbv
2018-11-08 11:40msvStatusresolved => assigned
2018-11-08 12:25gitNote Added: 0080932
2018-11-08 12:28nbvNote Added: 0080934
2018-11-08 12:28nbvAssigned Tonbv => msv
2018-11-08 12:28nbvStatusassigned => resolved
2018-11-08 17:19msvNote Added: 0080975
2018-11-08 17:19msvAssigned Tomsv => bugmaster
2018-11-08 17:19msvStatusresolved => reviewed
2018-11-08 17:41bugmasterNote Added: 0080981
2018-11-08 17:41bugmasterStatusreviewed => tested
2018-11-11 11:52bugmasterChangeset attached => occt master 080fcebf
2018-11-11 11:52bugmasterStatustested => verified
2018-11-11 11:52bugmasterResolutionopen => fixed
2018-11-11 12:01gitNote Added: 0081028

Notes
(0048569)
Timo   
2015-11-25 15:38   
This problem is similar to 0026532 because in both cases edges are meshed too coarsly. But the current Problem has nothing to do with the minSize parameter.
(0052404)
oan   
2016-04-05 17:14   
Initial shape contains triangulation for face and 3D polygon for free edges. 3D polygons has deflection 0.184044204640587 that is less than values specified in "steps to reproduce" - 0.715, 0.5, 0.3. BRepMesh checks deflection of existing polygonal data and generates new one only if it is greater than specified value. That is why much more appropriate polygons are generated when value 0.1 is used. Like this, it is necessary to clean up all existing data before call to incmesh in order to produce correct result.
(0069421)
mkv   
2017-08-15 18:55   
Problem described in issue is reproduced on current state of OCCT.
(0080659)
oan   
2018-11-02 18:30   
Please check on current master.
(0080835)
nbv   
2018-11-07 15:53   
The problem is still reproduced. See http://occt-tests/IR-2018-11-02-OCCT/Windows-64-VC14/bugs/mesh/bug26928.html [^]
(0080847)
oan   
2018-11-07 16:24   
Please note that results are different comparing to scenario given in Steps To Reproduce.
(0080848)
nbv   
2018-11-07 16:57   
Dear Markus,

In the current Dev version, you should use "tclean" command to vanish existing mesh (already stored in the file). After that, the shape will look OK.
(0080851)
git   
2018-11-07 17:00   
Branch CR26928 has been created by nbv.

SHA-1: 35bac4e9707e66d025daafecd9ac5ed1166d991d


Detailed log of new commits:

Author: nbv
Date: Wed Nov 7 16:56:57 2018 +0300

    0026928: Edges are meshed too coarsly
    
    Adding test case for the problem.
    The issue has been fixed by a patch for 0026106.
(0080873)
git   
2018-11-07 17:27   
Branch CR26928 has been updated forcibly by nbv.

SHA-1: 4cc36b23a46a182998326841c3dd6e55edcee296
(0080881)
git   
2018-11-07 17:54   
Branch CR26928 has been updated forcibly by nbv.

SHA-1: dd76be461adefc1407021cc40d4907f20100f90f
(0080898)
git   
2018-11-07 18:15   
Branch CR26928 has been updated forcibly by nbv.

SHA-1: ec90ab79cf7abd7673e263bd554824643ad7f0ba
(0080899)
nbv   
2018-11-07 18:16   
Dear Mikhail,

Please review the branch CR26928.

Test results are here:
Windows: http://jenkins-test-12.nnov.opencascade.com/view/MeshTest-master_NBV/view/TESTING/job/MeshTest-master_NBV-OCCT-Windows-64-VC14-opt-test-restart/HTML_20Report/ [^]

Linux: http://jenkins-test-12.nnov.opencascade.com/view/MeshTest-master_NBV/view/TESTING/job/MeshTest-master_NBV-OCCT-Debian80-64-opt-test-restart/HTML_20Report/ [^]
(0080926)
msv   
2018-11-08 11:40   
Please redesign the test:
- remove checkcolor command
- make view showing more detailed picture.
(0080932)
git   
2018-11-08 12:25   
Branch CR26928 has been updated forcibly by nbv.

SHA-1: 962b8ae099daad74abff5f2dfdae341fa45d7d7a
(0080934)
nbv   
2018-11-08 12:28   
Done. Please review the branch CR26928 again.
(0080975)
msv   
2018-11-08 17:19   
Reviewed.
(0080981)
bugmaster   
2018-11-08 17:41   
Update testing case
(0081028)
git   
2018-11-11 12:01   
Branch CR26928 has been deleted by inv.

SHA-1: 962b8ae099daad74abff5f2dfdae341fa45d7d7a