Mesh - display old brep is wrong

> I upgrade occ to version 7.5,I found a strange thing.
You description points to OCCT 7.3.0 vs OCCT 7.5.0, but your screenshot mentions OCCT 7.4.0. Which version you have actually tried?

I both tried,last year I upgrade to occ7.4,I found this problem.
When occ7.5 is released,I tried again, the problem exist!

Hello Author,

attached shape already contains triangulation computed and stored by elder version of OCCT and it seems incorrect anyway. It is possible to check it like this:

pload ALL
restore Attachment 1 (BREP) a
vinit
vsetdispmode 1
vdefaults -autoTriang 0
vdisplay
vfit

This means that described problem is not in version 7.5.0, but common since the version you used to create aforementioned shape.

Moreover, shape itself is invalid according to the report of checkshape:

pload ALL
restore Attachment 1 (BREP) a
tclean a
checkshape a

#On Shape faulty_1 :
#BRepCheck_No3DCurve
#On Shape faulty_2 :
#BRepCheck_No3DCurve
#On Shape faulty_3 :
#BRepCheck_No3DCurve
#On Shape faulty_4 :
#BRepCheck_No3DCurve
#On Shape faulty_5 :
#BRepCheck_UnorientableShape
#Shape faulty_1 on shape faulty_5 :
#BRepCheck_NoCurveOnSurface
#Shape faulty_2 on shape faulty_5 :
#BRepCheck_NoCurveOnSurface
#Shape faulty_3 on shape faulty_5 :
#BRepCheck_NoCurveOnSurface
#Shape faulty_4 on shape faulty_5 :
#BRepCheck_NoCurveOnSurface
#
#Faulty shapes in variables faulty_1 to faulty_5


Summarizing all from the above, BRepMesh is expected to build correct triangulation given that target shape contains no drastic deviations regarding shape validity. In the reported case shape does not contain either 3D curve or curve on surface. This could be considered as significant failure due to the fact that this data is required and triangulation is built upon it.

If you try to fix the model as follows, it will look as you expected:

pload ALL
restore Attachment 1 (BREP) a
tclean a
fixshape a a
vinit
vsetdispmode 1
vdisplay a
vfit

Another approach it to try to redesign initial model so it would be valid by default.

Good luck!

thank you
when I fixshape,my question is sloved

Dear Commenter 1, please close the issue.