[Regression to 7.2.0] Modeling Algorithms - Intersection fails in Occt 7.3.0

Dear Author, could you attach here the files to reproduce in BREP format?

Sure! Attachment 2 (BREP) shows the two shapes that are being intersected. Attachment 3 (BREP) is generated using 7.3.0 (there's nothing there...), and Attachment 1 (BREP) is generated using 7.2.0.

Thanks for looking into it and let me know if you need anything else from me!

If you swap the operands then the result is good.
So, here we see instability connected with the order of arguments.

The shape contains some faces built on planar bspline surfaces (degree in both U and V is 1).
If we convert them to be built on canonical planes (I used Canonical Recognition component https://www.opencascade.com/content/canonical-recognition) the result is good regardless of the order of the arguments.

Thanks for the workaround! Is it possible to fix the original instability?

There is nothing impossible. However, this task is not payed. Therefore it has very low priority.

Ok, what would be the process to turn this into a paid task? I can't seem to find a donation page or something

Please fill in contact form at https://www.opencascade.com/contact. The support manager will communicate you to discuss the ways of putting the bug into paid status.

This bug is classified as a regression. It will be fixed on account of internal OCC resources.

Branch [archived branch] has been created by Participant.

[revision removed]


Detailed log of new commits:

Author: emv
Date: Mon Jun 3 11:36:18 2019 +0300

    0030760: Modeling Algorithms - Intersection fails in Occt 7.3.0
    
    Use FORWARD orientation of edges and face when attaching pcurve from one edge to another.
    Test case for the issue.

Dear Mikhail, could you please review the git branch CR30760?
Test results - http://vm-jenkins-test-12.nnov.opencascade.com:8080/view/CR30760-master-emv/view/COMPARE/

Branch [archived branch] has been updated forcibly by Participant.

[revision removed]

Reviewed.

Combination -
OCCT branch : [archived branch]
master SHA - [revision removed]
[revision removed]
Products branch : [archived branch] SHA - [revision removed]
was compiled on Linux, MacOS and Windows platforms and tested in optimize mode.

Number of compiler warnings:
No new/fixed warnings

Regressions/Differences/Improvements:
No regressions/differences

CPU differences:
Debian80-64:
OCCT
Total CPU difference: 16283.950000000004 / 16313.930000000051 [-0.18%]
Products
Total CPU difference: 10489.97000000005 / 10490.14000000005 [-0.00%]
Windows-64-VC14:
OCCT
Total CPU difference: 17720.8125 / 17714.90625 [+0.03%]
Products
Total CPU difference: 12062.0 / 12054.984375 [+0.06%]


Image differences :
No differences that require special attention

Memory differences :
No differences that require special attention

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