Why do some back faces becom transparent for no reason?

I dont have cull back faces set but some times some back faces on only some objects, dont shade.

bug? or ?


Could be bad edges on a surface. Please post a file…

I’ve always found it to be related to edges. Pascal had a script about 5 years ago that easily fixes these. It was called ReTrimSurfaces. Maybe he has a newer Python version? If he doesn’t jump in here I will post the script.


RhinoScript ReTrim attached. It works some of the time… Save, then Drag and drop the rvb file onto Rhino to add


as an alias that runs the script…
ReTrim.rvb (7.2 KB)


Thanks for those reply’s all, and that script Pascal.