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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0030466||Community||[OCCT] OCCT:Modeling Algorithms||public||2019-01-31 17:34||2019-02-01 10:15|
|Platform||Windows||OS||VC++ 2015||OS Version||64 bit|
|Product Version||[OCCT] 7.3.0|
|Target Version||Fixed in Version|
|Summary||0030466: Problems removing non-isolated holes|
|Description||Noticed when working on CADProcessor: concerns BRepAlgoAPI_Defeaturing|
Problem when trying to remove a hole which is lying on more than 1 support face (the hole is at the intersection of multiple faces).
The algorithm fails to remove the hole.
|Steps To Reproduce||restore 2019-01-15_Intrados-HolesRemoved.brep a|
explode a F
removefeatures result a a_19 a_20 a_25 a_26
and documentation updates
|From a preliminary study, the input looks OK (the feature faces and adjacent faces numbers are correct).|
But the solid is not recreated properly, from BOPAlgo_MakerVolume::PerformInternal1, after BuildSolids call, only the bounding box is recreated, which leaves us with no result shape at the end.
|Tags||No tags attached.|
|Test case number|
|Attached Files|| 2019-01-15_Intrados-HolesRemoved.brep (910,293 bytes) 2019-01-31 17:34|
bug30466_extfaces.brep (166,251 bytes) 2019-02-01 10:15
The input shapes has a huge tolerance relatively the model size. Try the command 'tolsphere' in draw to see the tolerances of vertices:
It is not safe to pass such arguments into the modeling operations.
But even after reducing the tolerances of the shape with the following commands:
settolerance a 1.e-7 fixshape a a
the algorithms fails to remove the hole.
It seems the reason is the huge tolerance obtained by the Face/Face intersection algorithm when intersecting the extended faces filling the hole. These tolerances do not allow producing the correct volume.
Here is the script to see these intersection tolerances:
restore bug30466_extfaces.brep c explode c f bopcurves c_2 c_3 -2d # Tolerance Reached=0.53837672555709137
|2019-01-31 17:34||emei||New Issue|
|2019-01-31 17:34||emei||Assigned To||=> msv|
|2019-01-31 17:34||emei||File Added: 2019-01-15_Intrados-HolesRemoved.brep|
|2019-02-01 10:15||emv||Note Added: 0081983|
|2019-02-01 10:15||emv||File Added: bug30466_extfaces.brep|
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