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IDProjectCategoryView StatusDate SubmittedLast Update
0022445CommunityOCCT:Modeling Algorithmspublic2011-04-28 10:222013-12-19 14:00
ReporterszyAssigned Toabv 
PrioritynormalSeveritytrivial 
Status closedResolutionunable to reproduce 
OSAll 
Target Version6.7.0Fixed in Version6.7.0 
Summary0022445: The converted to bspline torus is failed to mesh
DescriptionBRepMesh meshes a torus with different radius, as a primitive surface and as
nurbs surface. Post from the Forum -
http://www.opencascade.org/org/forum/thread_20486/,
Below is a Draw script (developed by MSV) that repeats the simple program of Jerome:
for {set i 1} {$i <= 19} {incr i} {
  puts "radius: $i"
  dset defl $i*0.007*2
  ptorus t $i 1
  incmesh t defl
  set ntri [lindex [trinfo t] 3]
  puts "Prim Torus: $ntri"
  nurbsconvert nt t
  incmesh nt defl
  set ntri [lindex [trinfo nt] 3]
  puts "Nurbs Torus: $ntri"
}
It produces the following output in OCC 6.5:
radius: 1
Prim Torus: 2664
Nurbs Torus: 2994
radius: 2
Prim Torus: 1600
Nurbs Torus: 2232
radius: 3
Prim Torus: 1500
Nurbs Torus: 3100
radius: 4
Prim Torus: 1450
Nurbs Torus: 3634
radius: 5
Prim Torus: 1450
Nurbs Torus: 4572
radius: 6
Prim Torus: 1400
Nurbs Torus: 4976
radius: 7
Prim Torus: 1400
Nurbs Torus: 5800
radius: 8
Prim Torus: 1400
Nurbs Torus: 6542
radius: 9
Prim Torus: 1350
Nurbs Torus: 7778
radius: 10
Prim Torus: 1350
Nurbs Torus: 7612
radius: 11
Prim Torus: 1350
Nurbs Torus: 8034
radius: 12
Prim Torus: 1350
Nurbs Torus: 8544
radius: 13
Prim Torus: 1350
Nurbs Torus: 9116
radius: 14
Prim Torus: 1350
Nurbs Torus: 9878
radius: 15
Prim Torus: 1350
Nurbs Torus: 9982
radius: 16
Prim Torus: 1350
Nurbs Torus: 10096
radius: 17
Prim Torus: 1350
Nurbs Torus: 0
radius: 18
Prim Torus: 1350
Nurbs Torus: 0
radius: 19
Prim Torus: 1350
Nurbs Torus: 0

So, the behavior is almost the same:
with radius > 16 the converted to bspline torus is failed to mesh (nb of
triangles is 0).
It should be considered as a bug.
TagsNo tags attached.
Test case number

Activities

szy

2011-10-04 16:32

manager   ~0018314

The problem still exist with radius starting from 17.
See the post - http://www.opencascade.org/org/forum/thread_20486/:
"The mesh size problem is fixed in OCCT 6.5.1 but the segfault at radius 17 is still there."

oan

2011-10-05 12:27

developer   ~0018323

Dear Sergey,

This problem is not a BRepMesh bug, but BRepTools_WireExplorer. WireExplorer returns only one edge for converted torus with radius greater than 16 while it returns four edges for initial shape. BRepMesh_Classifier waiting for closed wire, but since WireExplorer returns just one edge (though there are four really) Classifier consider a hole and brakes further computations.

oan

2011-10-05 12:51

developer   ~0018324

checkshape print out the following results:

#initial shape
checkshape t
##=>This shape seems to be valid

#converted shape
checkshape nt
##=>On Shape faulty_1 :
##=>BRepCheck_UnorientableShape
##=>Shape faulty_2 on shape faulty_1 :
##=>BRepCheck_NotClosed
##=>
##=>Faulty shapes in variables faulty_1 to faulty_2

abv

2013-06-06 22:59

manager   ~0024679

The problem seems to be not reproduced in OCCT 6.5.4-6.6.0, could you please confirm? Another point is that in OCCT 6.6.0 it works visibly slower than in 6.5.x, and produces more triangles (>6000 vs 1980) -- is that justified?

oan

2013-06-24 17:01

developer   ~0024846

Dear Andrey,

I confirm, bug is not reproduced since OCCT 6.5.3 and up to current master.
Increased number of triangles is justified by fix for issue 0023184.

I suppose that this bug can be closed.

Issue History

Date Modified Username Field Change
2011-08-02 11:31 bugmaster Category OCCT:MOA => OCCT:Modeling Algorithms
2011-10-04 16:32 szy Note Added: 0018314
2011-10-04 16:32 szy Assigned To bugmaster => pdn
2011-10-04 16:32 szy Status acknowledged => confirmed
2011-10-05 09:05 pdn Assigned To pdn => oan
2011-10-05 09:05 pdn Status confirmed => assigned
2011-10-05 09:05 pdn Fixed in Version EMPTY =>
2011-10-05 09:05 pdn Target Version => 6.5.3
2011-10-05 09:05 pdn Description Updated
2011-10-05 12:27 oan Note Added: 0018323
2011-10-05 12:51 oan Note Added: 0018324
2011-10-05 14:54 abv Assigned To oan => jgv
2011-10-21 16:53 szy Resolution suspended => open
2012-03-12 07:32 abv Target Version 6.5.3 => 6.5.4
2012-10-23 19:29 abv Target Version 6.5.4 => 6.6.0
2012-11-09 09:49 abv Category OCCT:Modeling Algorithms => OCCT:Mesh
2013-02-27 17:28 oan Category OCCT:Mesh => OCCT:Modeling Data
2013-02-28 11:07 jgv Category OCCT:Modeling Data => OCCT:Mesh
2013-02-28 11:07 jgv Assigned To jgv => epa
2013-02-28 11:13 jgv Category OCCT:Mesh => OCCT:Modeling Algorithms
2013-02-28 11:13 jgv Assigned To epa => jgv
2013-03-01 21:34 abv Target Version 6.6.0 => 6.7.0
2013-06-06 22:59 abv Note Added: 0024679
2013-06-06 22:59 abv Assigned To jgv => oan
2013-06-06 22:59 abv Status assigned => feedback
2013-06-24 17:01 oan Note Added: 0024846
2013-06-24 17:01 oan Assigned To oan => abv
2013-12-19 12:18 bugmaster Status feedback => closed
2013-12-19 12:18 bugmaster Resolution open => unable to reproduce
2013-12-19 14:00 bugmaster Fixed in Version => 6.7.0