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Archived issue #0021968

BRepTools_WireExplorer gives different number of edges in dependance of order of edges in wire.

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Description

BRepTools_WireExplorer gives different number of edges in dependance of order of
edges in wire.(following OCC21771)

Draw command "checkshape" gives the different results in dependence of order of
edges.
Draw[9]> restore badf.brep f1
f1
Draw[10]> small
Draw[11]> fit
Draw[12]> donly f1
f1
Draw[13]> fit
Draw[14]> restore badf2.brep f2
f2
Draw[15]> display f2
Draw[16]> fit
Draw[17]> checkshape f1
On Shape faulty_1 :
BRepCheck_UnorientableShape
Shape faulty_2 on shape faulty_1 :
BRepCheck_NotClosed

Faulty shapes in variables faulty_1 to faulty_2


Draw[18]> checkshape f2
This shape seems to be valid

Shapes from file badf.brep and badf2.brep differ only by order of edges.

Public activity

4 archived notes

Participants are labeled by their role within this record.

01Commenter 1
Problem is not reproduced on current state of OCCT
02Commenter 1
It is really :

Draw[29]> invert f1
Draw[30]> checkshape f1
This shape seems to be valid

fi1 becomes valid if change orientation sub-shapes.

But shape f2 valid only because big tolerance

Draw[33]> tolerance f1
Tolerance MAX=3.3081047481749302 AVG=1.0587528038344109 MIN=9.[revision removed]-008
FACE : MAX=9.[revision removed]-008 AVG=9.[revision removed]-008 MIN=9.[revision removed]-008
EDGE : MAX=0.15031614050091399 AVG=0.069333319845787472 MIN=9.[revision removed]-008
VERTEX : MAX=3.3081047481749302 AVG=1.6858066338080242 MIN=5.[revision removed]-005

Draw[34]> tolerance f2
Tolerance MAX=3.3081047481749302 AVG=1.0587528038344109 MIN=9.[revision removed]-008
FACE : MAX=9.[revision removed]-008 AVG=9.[revision removed]-008 MIN=9.[revision removed]-008
EDGE : MAX=0.15031614050091399 AVG=0.069333319845787486 MIN=9.[revision removed]-008
VERTEX : MAX=3.3081047481749302 AVG=1.6858066338080242 MIN=5.[revision removed]-005

See attached pcurve.png

Is there since to consider this case as bug????? Or somple close it???
03Commenter 3
I confirm different behavior of checkshape after inverting the face. This is a bug and it needs additional investigation.
04Commenter 4
Problem described in issue is reproduced on current state of OCCT.

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