Hi PaQ, well I guess for now if rendering in Modo you will need to force some dicing of long polygons into smaller pieces to reduce those artifacts.

It seems like it would be a good thing to report to them, because it doesn't really have to be that way, as you can see from the Cinema4D examples.

That kind of mach banding artifact usually happens in Gouraud real-time shading because in that shading method the normals are only evaluated against the full light sources just at the polygon's vertices, and then those colors blended throughout the polygon.

It kind of looks like you're getting that same kind of effect in the full render...

- Michael