I know Rhino will always use triangles for trimmed and joined edges of a polysrf. I also know Rhino starts with initial grid quads on a srf. My question is, how can I keep those initial grid quads and only have triangles at the trimmed joints?
I have read all the meshing FAQs and I’m still getting triangles everywhere, like in the middle of a curved srf and at the seam of two untrimmed srfs.
one thing you can try is to turn OFF the refine option, but it has been always the case that in areas near trims there must be a few triangulated faces. Only if you extract the mesh, you might get rid of more triangles by using the command _QuadrangulateMesh with the option values for Planarity=60 and Rectangularity=1000. These are the maximum values.