I apologize to all of you who are avid board watchers, as I erroneously posted this to the General list first. I'm not trying to flood y'all, I'm just trying to get my question to as many of those who can answer as possible *smile
Alright folks, this is weird. I've got a 12000 poly character that I have bound to a skeleton via smooth skinning. Opening the 'paint weights' tool shows me a nicely-painted skin (if i do say so myself grin).
I would now like to reduce the polygon count of said skin/skeleton combination. A quick click on the 'Edit polygons->reduce' button gives me a decimated character. Great! Not only is it lower poly-count, but it moves just how I want it. Oh, but that hand looks a little strange - I'm going to go back into the paint skin weights tool and fix it. Doink!
Whaoh! Why is the hip affecting the top of the head? Why are none of the joints affecting their proper vertexes anymore? Hrm. A little digging revealed that while maya reduces the number of polys with this operation, it does not re-arrange the weights of the vertices to accomodate for the smaller poly-count! What does this mean, you ask?
Let's start with a 200-vertex character, and say the hips are assigned to vertex 0-50 (1.0 weight for the sake of completeness), and the chest is assigned to 51-200. Let's reduce the poly count by 75% (giving us a final result of 50 vertexes). Maya has now re-numbered the vertices from 1-200 to 1-50. Okay, but it did not rearrange all of the weights! The hips (which used to have weights for 1-50) now still have weights for 1-50, and the chest (which affected 51-200) now is affecting points which don't exist anymore! This means when i pop open the paint weights tool and select the hips, they look like they are affecting the entire mesh (points 1-50). The data structure that keeps track of the joint weights hasn't changed, and it looks like the paint weights tool references the 'old' data structure. The mesh's history allows for it to continue moving in its old fashion, but by golly, i want a trick to change the data structure so that when i paint weights with the decimated model, the chest is (in the data structure - and thus the paint weights tool) affecting the spots it used to...
So my question - does anyone know of a way to make the newly-decimated mesh's vertex weights rearrange themselves? True, because of the history the mesh moves fine in maya, but exporting vertex weights to an engine when they aren't right is, well, ugly to say the least...
Thank you dearly for any help - I'm totally open to writing plugins and scripts, so make me work smile.
Andrew Gardner
University of Wisconsin, Madison