Sadly I have only come across this issue a week after your visit to London, but no matter!
Problem: Inconsistencies with how a quad mesh is represented in Rhino 6.
Software: Rhino 6.2.18065.11031; Grasshopper 1.0.0004
Steps to reproduce:
- Create a flat, planar single quad mesh face on the XY plane in Rhino (clicking by hand)
- Under Properties -> Details… you can see it has 4 vertices and 1 face
- Reference the mesh into Grasshopper. The referenced mesh also has “(V:4 F:1)”
- The Mesh Edges component in GH also only recognises 4 edges (as per this discussion)
This is all terrific and expected.
- Move one of the vertices of the mesh up or down (Z direction), to create a twisted quad mesh.
- Under Properties -> Details… you can see it still has 4 vertices and 1 face
- The referenced mesh in GH also still has “(V:4 F:1)”
- The Mesh Edges component in GH also only recognises 4 edges
This is all also terrific and expected.
- Create a new quad mesh in Rhino that is not planar (clicking by hand)
- Under Properties -> Details… you can see that this quad mesh has 4 vertices and 2 faces
- Reference this quad mesh into Grasshopper. This time the referenced mesh has “(V:4 F:2)”
- The Mesh Edges component in GH still only recognises 4 edges as before
The fact that this quad mesh has two faces is not expected and thus not so terrific.
I can see how the argument for only ever having triangle meshes (and thus n-gons are merely composed of triangles beneath the surface) is a reasonable one, but I kinda like having quad meshes as a possibility.
More importantly, I think it’s critical that quad meshes are represented in a consistent manner, and not dependent on the circumstances of their creation. Thoughts?