Hi!

Lets say I wanted to promote prim UVs to replace the UVs for texturing, how would I go about this?

-Olivier

you probably can use s and t global variables in shader, which correspond to parametric uv coords

or if you want to have it as vertex uv attrib in SOPs you can do
Vertex Wrangle:

Thanks! I'm using arnold so I think the xyzdist option is what I'm looking for.

I don't think xyzdist will work for polygon meshes. Since the shared points need to have different values for the parametric uvs.

For quads, you can use vertexindex to retrieve the corner number within the quad, and then use it to index into a barycentric coord array.

e.g.:

For triangles, I think you might need to duplicate one of the corner vertices to replicate mantra behavior. ngons shade completely differently as the u represents the index, and v is the distance from the barycenter, which isn't possible to represent as uv coordinates without triangulating.

jsmack
I don't think xyzdist will work for polygon meshes. Since the shared points need to have different values for the parametric uvs.

why wouldn't it?
it's using current prim as a group scope, so each vertex only gets primuv coords from its own prim

EDIT: I mean you may be right for ngons that wrap onto itself, like single polygons with bridged holes, but I assume that's not the case

tamte

jsmack
I don't think xyzdist will work for polygon meshes. Since the shared points need to have different values for the parametric uvs.

why wouldn't it?
it's using current prim as a group scope, so each vertex only gets primuv coords from its own prim

EDIT: I mean you may be right for ngons that wrap onto itself, like single polygons with bridged holes, but I assume that's not the case

Ah, scoping it to the primitive may work for quads and triangles, but not if they have coincident points. It also won't work for ngons because the v value is the same for all of the vertices. It's also a sort of raytracing and will be a lot slower than indexing an array.