It is unclear from description how 7.4.brep file has been produced from test.igs.
I'm unable producing such BREPs by reading IGES file using OCCT 7.3 and OCCT 7.4.
Reading IGES anew produces a valid shape, while both attached BREP files have an issue
(after fixshape both shapes look fine in 3D Viewer):
-- The Shape b1 has problems :
Check Count
------------------------------------------------
No 3D Curve .............................. 4
Unorientable Shape ....................... 1
------------------------------------------------
There couldn't be a guarantee for BRepMesh producing a good mesh for invalid shape,
so I would first try to determine why your shape files have problems.
Mon, 12/23/2019 - 12:52
Could you please attach initial IGES file In order we can analyze this case and give you answer on the your question.
Best regards
Tue, 12/24/2019 - 04:27
v7.3 and v7.4 import igs is right!I use v7.3 to save shape to brep, and open in v7.4 is wrong! Files below!
Sat, 12/28/2019 - 03:42
Is it occ7.4 bug?
Sat, 12/28/2019 - 12:30
It is unclear from description how 7.4.brep file has been produced from test.igs.
I'm unable producing such BREPs by reading IGES file using OCCT 7.3 and OCCT 7.4.
Reading IGES anew produces a valid shape, while both attached BREP files have an issue
(after fixshape both shapes look fine in 3D Viewer):
There couldn't be a guarantee for BRepMesh producing a good mesh for invalid shape,
so I would first try to determine why your shape files have problems.
Fill free reporting the issue on Bugtracker:
https://dev.opencascade.org/index.php?q=home/get_involved