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0027251Community[OCCT] OCCT:Data Exchangepublic2016-03-11 13:552020-09-17 20:02
Markus 
gka 
normalminor 
newopen 
[OCCT] 7.0.0 
[OCCT] 7.6.0* 
bugs step bug27251
0027251: Shape becomes invalid when exported to STEP and imported back
Shape before export to STEP is valid, but after import becomes invalid.
restore cc.brep c

whatis c

checkshape c

stepwrite 0 c c.stp

stepread c.stp r *

whatis r_1

checkshape r_1

No tags attached.
? cc.brep (479,000) 2016-03-11 13:55
https://tracker.dev.opencascade.org/
Issue History
2016-03-11 13:55TimoNew Issue
2016-03-11 13:55TimoAssigned To => gka
2016-03-11 13:55TimoFile Added: cc.brep
2016-10-26 11:07gkaTarget Version7.1.0 => 7.2.0
2017-05-31 15:40TimoReporterTimo => Markus
2017-07-27 11:15abvTarget Version7.2.0 => 7.4.0
2017-08-21 18:17mkvTest case number => bugs step bug27251
2017-08-21 18:17mkvNote Added: 0069728
2019-04-03 12:09MatthiasNote Added: 0083380
2019-07-10 22:00abvTarget Version7.4.0 => 7.5.0
2020-09-17 20:02gkaTarget Version7.5.0 => 7.6.0*

Notes
(0069728)
mkv   
2017-08-21 18:17   
Problem described in issue is reproduced on current state of OCCT.
(0083380)
Matthias   
2019-04-03 12:09   
Original shape is non-manifold (corners touch each other).
In case the original shape is splitted into two faces, the issue doesn't occur.

When importing the STEP-file, are there any repairing mechanisms trying to repair some intersections and can't handle self-intersections due to non-manifold geometry?

The issue occurs also with IGES and with Parasolid (via CADExchanger).