Painting skin weights

blaaaaaaaaaaaaaaaaah,

that is how I feel today, just blah and it doesn't help that we have yet another cold , gray day here in Seattle.

So what have I been up to lately? Painting skin weights and creating blend shapes.

WTF is that? in order to create a 3d character you create a 'mesh' which is essentially the skin. Then you create a system of 'bones', 'joints', and controllers that mimic the movement of the human body or an elephant or a car for that matter. You then have to attach the mesh to that system so the bones and joints drive the skin. Maya has a push button for this called 'smooth skinning', you select the mesh, select the bones and hit a button and voila! The problem is that this system doesn't do a very good job of assigning which bone affects what part of the mesh. A mesh is a collection of vertices, and each vertex can be attached to several bones and joints which can make for very smooth and realistic looking skin as a charcter bends an arm or moves its foot or it can result in a mess. Maya's push button system results in a mesh. So in order to fix that you have to go through each bone in the rig and 'paint' how it influences the skin/mesh. It is a tedious, painstaking process that is so boring. It is somewhat rewarding when you rotate an arm or bend a knee and it looks like it should.

I spent probably 15 hours over the weekend painting skin weights for one character. And to be honest I am not 100% happy with the results. May have to go back and tidy up but for now I am moving on to the next character. Eight to do before I can actually start animating. ugh. but it has to be done.

The image is a screenshot of the process. In the image white means a value of 1 or 100% weight and black is 0 or 0% weight. So in this shot you can see that the jaw is not associated with the same joint that the head is. In this case I was painting the jaw so that it opens and closes without the mesh binding or breaking. Exciting stuff eh?