Hi andrew - it's only possible to generate planar n-gons on surfaces that are themselves planar.

Any kind of curved surface will have some amount of non-planarity to the n-gons that are generated from it. That's just what happens when vertices are placed at intervals along a curved surface.


It kind of looks like you've got a couple of separate problems there - your first screenshot there has the slight dark edge - that looks like it could be an n-gon triangulation problem.

I'm not really sure what the second problem that you are showing is though - that does not seem to be likely to be a triangulation problem but instead may be some kind of irregularity in your UV mapping or something along those lines.


I'm also not really sure why many other people typically use n-gons in Modo without running into problems. It looks like you are using some kind of heavy bump map or displacement map? How are you applying the UV mapping for that?

What about a totally plain non-textured render, do you see any artifacts at all on that style of rendering or not?

If the particular mapping/rendering technique that you want to use does not work well in Modo with N-gons then I guess that your best bet would be to use Quads & Triangles instead, if that solves the problem for you.

- Michael