Hi Max - tessellating a generic trimmed surface to quads is a quite difficult task. It involves placing quads initially along trim boundaries and then trying to grow or shrink them across the surface and dealing with a lot of issues when different growing boundary sides crash into one another. It's something that I'd like to attempt in the future but will require quite a lot of work to do very well.

Then if you're actually looking for _planar_ quads instead of just any quad with its 4 corner points on a curved surface (making them normally slightly warped and not planar), that's another pretty entirely different thing as well. For that I'd recommend paneling tools in Rhino, that is a specialized toolset for doing planar panelization.

- Michael

Thanks Michael.
Even if the polygons were warped it would be fine.
Actually I did want to try and implement some sort of simple paneling tools for moi, and yeah tessellation is the first task to do. I did a study over the algorithms though.
M.