problem with LSCM

General Forums Blender and CG Discussions
1

Using LSCM for the first time today, I’m noticing that it tends to mess up big-time on quads that are shaped like tri’s. (four-vertex triangles) Usually LSCM sends one of the verts on the 'tri-quad’way over to the other side of the UV map, connecting to a vert on the wrong side of a seam. Putting in more seams around the area doesn’t help.

It does this whenever I need to put a seam adjacent to one of these tri-quads.

I’ve managed to fix some of these trouble spots by reconfiguring the mesh to eliminate these four-vertex triangles but I’m wondering if this is a known problem. Are four-vertex triangles not intended to be used in UV mapping, or is this just an LSCM problem? Sometimes it’s really convenient to use ‘tri-quads’ in a mesh but if LSCM can’t handle it then that will have to change the way I model.

2

I’ve never seen this myself, but, I can imagine why it happens. The model is triangulated before unwrapping. If the quad is shaped as a tri, there can be one triangle with near zero angles, making things unstable.

The solution would be to triangulate the quad in the other direction. I’ll add a check for this to the code. Could you post or send me a .blend with a mesh showing this behaviour, so I can verify? My email is (blendix-at-pandora-dot-be). Thanks.

3

No problem, I’ll send it there. :slight_smile:

I think I may have accidentally posted this in the wrong forum too, heh.