Real-Time Physics Simulation Forum

I made a cloth simulation using c++. It uses implicit backward euler integration and continuous collision detection for cloth-object and cloth self-collision. Strain limiting was used to simulate inextensible cloth. BVH/AABB was implemented to avoid n^2 collision checking. Rendering was done in Maya using AnimOBJ(http://code.google.com/p/animobj) which is made by myself as well.

Below is a link to the short video.

http://www.youtube.com/watch?v=YVhD2d2wWHU

I am currently trying to implement global collision treatment methods based on papers below.

• Accurate Collision Response on Polygonal Meshes(http://www.miralab.ch/repository/papers/46.pdf)
  
  Globally coupled collision handling using volume preserving impulses(http://www.math.ucla.edu/~jteran/papers/SMT08.pdf)
  
  Robust Treatment of Simultaneous Collisions(http://www.cs.columbia.edu/cg/RTSC/)

If you have some experience with global collision treatment, please share your idea with me. I implemented the second one (volume preserving impulses) and have some problem with convergence. I believe the matrix is not really definite and need to use GMRES. I am using conjugate gradient now.

Also the first paper is somehow confusing.

Thank you.

Since my previous posting, I've been developing my own simultaneous proximity and continuous collision handling method for cloth simulation. I tried a couple of approaches like ones linked above and was not satisfied much. Below is a link to my current approach in youtube.

http://youtu.be/6yKrcV16k6A

The idea is basically creating a big linear equation and solve it rather than treating individual collisions iteratively until it converges. It is kind of similar to LCP but I am using impulses and proximity information in position level rather than velocity level. The matrix of linear equation can be over-constrained and ill-conditioned due to the complexity and irregularity of collision distribution. I overcome the problem by using conditional regularization. This research is still on-going but I just want to share it.

Attaching a screenshot to show the stress test with more clothes.