Cant trim Surface, grasshopper automatically full it

[Michael_Pryor (ekim)]

This question is so exhausting, this forum really needs some good FAQ page. See here and learn the difference between trimmed and untrimmed surfaces.

Lunchbox Triangular surface

See these threads. What you are dealing with is are trimmed surfaces. Trimmed surfaces are almost always evaluated by their untrimmed underlying Nurbs(4 point) surface, it is how Nurbs works. This isnt a Grasshopper knowledge issue, it is a Rhino knowledge issue. Check this: Rhino - Download - Rhino Level 2 Training Guide and Models http://v5.rhino3d.com/forum/topics/trimmed-versus-untrimmed-surfaces

I also suggest doing some intro tutorials on Rhino and Grasshopper before diving into plugins.