CGAL build fails

[vandenzel]

Error message:

ERROR: CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: e->incident_sface() != SFace_const_handle() File: /opt/mxe/usr/x86_64-w64-mingw32.static/include/CGAL/Nef_S2/SM_const_decorator.h Line: 326

Probably has to do with polygons.

[raboof]

How are you triggering this? OpenSCAD preview, render and export to STL all seem to work for me.

http://forum.openscad.org/CGAL-what-does-this-mean-td21992.html mentions this issue in relation to importing STL

[vandenzel]

I'm running OpenSCAD version 2015.03-2. Maybe a bug.

[vandenzel]

Now installed OpenSCAD version 2019.05. Stilll the same bug. Maybe Windows?

[vandenzel]

Same issue on another windows machine with 2019.05

[raboof]

Do you get the error on startup? Or when you load the file or perform an operation?

[vandenzel]

When I render the design (F6). Preview (F5) works fine

[raboof]

Ah - looking closer I do have the same problem, and it prevents the 'obverse' side from being rendered correctly. Interesting!

[vandenzel]

It could have something to do with illegal collision of faces or vertices. A redesign using polygons instead of dropping squares gave the same error.

[raboof]

You'd expect OpenSCAD to have enough information to resolve the collision though... or at least give a better error msg