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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0023400||Community||[OCCT] OCCT:Mesh||public||2012-08-24 11:48||2014-11-11 13:01|
|Priority||normal||Severity||just a question|
|Product Version||[OCCT] 6.5.3|
|Target Version||[OCCT] 6.8.0||Fixed in Version||[OCCT] 6.8.0|
|Summary||0023400: Triangulation of thin ring contains gap|
|Description||Hi, I', wondering whether this behaviour is valid. I triangulate a thin ring using the following meshing parameters|
deflection (relative) = 0.5
angular_deflection = 0.6
As you can see in the attached screenshot, a gap appears in the ring. I would have expected that the triangulation is always preserving the topology of the shape?
|Tags||No tags attached.|
|Test case number||bugs vis(004) bug23400|
|Attached Files|| thinring.brep (13,778 bytes) 2012-08-24 11:48|
thinring.png (11,114 bytes) 2012-08-24 11:49
overlapping.png (3,727 bytes) 2013-03-07 17:24
Problem is not reproduced on OCC build based on the current master, ring appears without any gaps.
From the other side I suppose this case is caused by overlapping between the discretized representations of the inner and the outer circles forming the ring (please see the attached screenshot). In this situation when the square of an appeared loop is too small and the distances between the intersection points and a sampling point are within the deflection this loop may be replaced by a single link shown as a gap.
As a possible solution the angular deflection should be decreased to provide more precise sampling of the circles and avoid intersections.
I have faced a problem during visualization of the attached shape. Could you please investigate?
Steps to reproduce:
restore thinring.brep a
# An exception was caught 00816588 : Standard_NumericError: FLT MULTIPLE TRAPS
#(possible overflow in conversion of double to integer)
# ** Exception ** 00816588 : Standard_NumericError: FLT MULTIPLE TRAPS
# (possible overflow in conversion of double to integer)
edited on: 2014-07-09 15:41
>> I have faced a problem during visualization of the attached shape.
dedicated issue 0025063 has been registered for this regression (since it is irrelevant to this bug description).
Please do not set top view (vtop) as temporary workaround.
|Oleg, could you please re-check the actual status of the issue?|
edited on: 2014-09-26 16:04
Should not appear on current master. Current implementation of BRepMesh_Classifier tries to prevent appearence of such cases.
Moreover, detailed description of the matter is given in first note.
please create corresponded test case and check.
Branch CR23400 has been created by mkv.
Detailed log of new commits:
Date: Wed Oct 8 20:32:16 2014 +0400
Test case for issue CR23400
Test cases bugs/vis(004)/bug23400 is created and pushed to new branch CR23400 of occt git-repository.
Test cases bugs/vis(004)/bug23400 is OK.
Branch CR23400 has been deleted by inv.
occt: master e2fd181c
Timestamp: 2014-10-08 16:32:16
|0023400: Triangulation of thin ring contains gap
Test case for issue CR23400
|add - tests/bugs/vis/bug23400|
|2012-08-24 11:48||Fabian Hachenberg||New Issue|
|2012-08-24 11:48||Fabian Hachenberg||Assigned To||=> jgv|
|2012-08-24 11:48||Fabian Hachenberg||File Added: thinring.brep|
|2012-08-24 11:49||Fabian Hachenberg||File Added: thinring.png|
|2012-11-09 10:51||abv||Category||OCCT:Modeling Algorithms => OCCT:Mesh|
|2013-03-07 17:24||oan||Note Added: 0023629|
|2013-03-07 17:24||oan||File Added: overlapping.png|
|2013-03-07 17:24||oan||Assigned To||jgv => Fabian Hachenberg|
|2013-03-07 17:25||oan||Status||new => feedback|
|2013-07-23 12:25||oan||Relationship added||related to 0024084|
|2014-07-09 12:49||oan||Note Added: 0030024|
|2014-07-09 12:49||oan||Assigned To||Fabian Hachenberg => kgv|
|2014-07-09 13:42||kgv||Relationship added||related to 0025063|
|2014-07-09 13:57||kgv||Note Added: 0030027|
|2014-07-09 13:57||kgv||Assigned To||kgv => oan|
|2014-07-09 15:41||kgv||Note Edited: 0030027||View Revisions|
|2014-09-12 10:04||abv||Target Version||=> 6.8.0|
|2014-09-26 06:16||abv||Note Added: 0032179|
|2014-09-26 16:03||oan||Assigned To||oan => bugmaster|
|2014-09-26 16:03||oan||Note Added: 0032250|
|2014-09-26 16:03||oan||Status||feedback => assigned|
|2014-09-26 16:04||oan||Note Edited: 0032250||View Revisions|
|2014-09-26 16:24||abv||Status||assigned => feedback|
|2014-09-29 15:42||bugmaster||Assigned To||bugmaster => mkv|
|2014-10-08 20:32||git||Note Added: 0032847|
|2014-10-08 20:46||mkv||Note Added: 0032851|
|2014-10-08 20:46||mkv||Assigned To||mkv => bugmaster|
|2014-10-08 20:46||mkv||Status||feedback => tested|
|2014-10-08 20:46||mkv||Test case number||=> bugs vis(004) bug23400|
|2014-10-13 17:52||bugmaster||Changeset attached||=> occt master e2fd181c|
|2014-10-13 17:52||bugmaster||Status||tested => verified|
|2014-10-13 17:52||bugmaster||Resolution||open => fixed|
|2014-10-21 16:42||git||Note Added: 0033419|
|2014-11-11 12:43||aiv||Fixed in Version||=> 6.8.0|
|2014-11-11 13:01||aiv||Status||verified => closed|
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