I want to blend an object from one shape to another (a classic blendshape problem) but rather than transforming the whole object simultaneously, I want to introduce the deformation through a ripple across the surface.
Ideally, my nodegraph abstract would look something like this:
blend target -> master blend
animated 3d texture sample (gradient / noise / whatever) -> deformer weights -> master blend
Unfortunately, I don’t know how to do texture samples OR per-vertex weight data assignments in the graph editor. (I’ve hacked into vertex colour once or twice, but my solution was ugly, requiring a separate connection for each vert… and in any case, it doesn’t seem to apply to weights)
I considered hacking the problem with mel (say, having an expression traverse the vertex list each frame, finding and assigning the correct deformer weight values for each vertex)… but then I realized, I don’t even know how to do that! (set deformer per-vertex weight values via mel, that is)
The listener isn’t being very informative. Nor the help. I guess I’ll go parse maya Ascii files for hints. In the meantime, forums to the rescue?
Before you ask:
The problem must be solved on the verts, because I want to be able to bake the whole thing as vertex animation when I’m done. Render-time solutions won’t help.
I want the transition to be smooth, and I want to be able to iterate at a high level. Breaking the transition down into a series of hand-painted weightmaps is not a viable compromise.