   Cloth Collision Detection
  Okay, I have this cloth I made using Verlet Particle Itegration. It's just a bunch of particles with relaxed constraints to allow the cloth to stretch. Now say I have a sphere, and would like the two to be able to collide with each other. I would also like the cloth to be able to collide with its self, and stop going through its self. Anybody have any directions in which to point me? The cloth is a simple quad:-------|\|\|\|-------|\|||\|-------Thanks guys!CD   
  http://www.darwin3d.com/gdm1999.htm#gdm0599Article I wrote in 1999 about cloth.  Covers collision response with spheres and planes.  Easy to extend.  Cloth-cloth collision can be pretty easy to implement but is very tricky to do fast since it is an n-squared problem with the number of cloth nodes.  Best to avoid doing if possible.   ;How to ask questions, i.e. what *is* your question?   ;Quote:Original post by JeffLanderhttp://www.darwin3d.com/gdm1999.htm#gdm0599Article I wrote in 1999 about cloth.  Covers collision response with spheres and planes.  Easy to extend.  Cloth-cloth collision can be pretty easy to implement but is very tricky to do fast since it is an n-squared problem with the number of cloth nodes.Pretty easy? how? I would like to here more.The best attempts I’d seen are using image precision with hardware acceleration, only worth for siggraph demos of the year that very quickly fall into oblivion. Nothing really worth trying;  I meant that you can pretty easily do it the brute force way.  Treat each node as a sphere and keep every node from interpenetrating the cloth surface.  The hard part is doing it in an actually useable way for anything but very small patches.  There is a lot of research on this problem though including some of the techniques you mentioned but also lots of the standard collision space partitioning and optimization methods.  But none of that is very easy.That is why I suggested if you are just starting with this, begin with the cloth-environment collision and once you are comfortable in that space, the other stuff can be added.  Google "cloth self collision" for tons of info.   ;  Try the following article for self-collision and also a very good discussion on the overall cloth simulation subject.http://www.mpi-inf.mpg.de/~bargmann/research_cloth.htmMyself, I'd skip with the self-collision and try tackling sphere or other bounding volume collision before getting into self collision.Shadx   