Tim Glover wrote:
> 
> I'm hoping to create my own simple character animation system and need
> some guidance in joint deformation.  I'm looking for some
> algorithms/conceptual explanations for deforming meshes around "joints"
> in a bones animation style system.  A web search gives only leads to
> sales of professional packages (and "Warez houses").  Anybody got some
> leads on the following:
> 
> 1) how to scale deformation as distance from joint increases
> 2) how to treat interpenetration of meshes
> 3) how to add gridding on expanding side of joint to preserve shape
> 
> I'm a FORTRAN programmer with nearly 20 years experience throwing
> formulas around, so hairy math is no problem.  I'm also very "creative"
> at crafting bizarre data structures within its limited repetoire.  In
> short - not a newby, not afraid of heavy comp-sci stuff.  Just not
> familiar with bending, deformable meshes.

You might want to try h-splines, possibly combined with Catmull-Clark
surfaces.  Check the Dragon Wing,
http://www.cs.ubc.ca/nest/imager/contributions/forsey/dragon/top.html. 
In particular check the page there on multiresolution surface
approximation http://www.cs.ubc.ca/spider/forsey/Approx/App_1.html. 
Also check out the paper by Hoppe, DeRose, et. al. in Tony DeRose's
recent papers at http://www.cs.washington.edu/homes/derose/papers.html. 
Finally, check out the Online Geometric Modelling Notes at
http://graphics.cs.ucdavis.edu/CAGDNotes/CAGD-Notes.html for a lot of
useful algorithms and general info.  In particular read the page on
Catmull-Clark surfaces at
http://graphics.cs.ucdavis.edu/CAGDNotes/Catmull-Clark/Catmull-Clark.html. 
Have fun.

Jerry Anning
cle### [at] dholcom

Post a reply to this message