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Actually these two methods are basically the same. As the AMS article states "the steady-state temperature distribution of some region in space is described by
by tfg 17y ago
Actually these two methods are basically the same. As the AMS article states "the steady-state temperature distribution of some region in space is described by a harmonic function." If you look at the method of relaxation described in the ams article, "move across the grid and replace the value of the function at a point by the average of adjacent points," it's the same as the method described in the Wolfire article, "set each voxel's heat to a weighted average of its neighbors' heat."
- sparky 17y agoYou're right, though I think the implementations differ in that Wolfire uses skeletons made of bones (line segments) and Pixar uses a polygonal cage mesh as the skeleton. It is quite possible that if you view the cage mesh as the 3D extrusion of a Wolfire-style skeleton, the results are exactly equivalent, but I'd have to think about it more. OT: what are the pros/cons of the two character modeling approaches (cage vs. skeleton)?
- JabavuAdams 17y agoPerhaps its easier for animators to see the influence of a cage on a vertex, rather than a bone? I was wondering about this. The cage is a nice wire-frame around the object of interest, and you can easily see how close the skin is to the cage, for some kind of intuition about influence. With bones and vertex to bone weighting, you'd need some other visualization (like false-colour on the vertices) to show how much each vert is influenced. Also, the cage seems to remove the conceptual problem of a vertex being driven by multiple bones. Hmmm. This is timely. Thanks!
- aufreak3 17y agoYes they are the same, but the harmonic function formulation seems a bit more more appealing because it focuses on the end result as opposed to the process.