1. This paper describes a cloth simulation system that can stably take large time steps.

2. The bottle-neck in most cloth simulation systems is that time steps must be small to avoid numerical instability. Traditional cloth simulation systems use explicit methods to advance the simulation. However, explicit methods are ill-suited to solving stiff equations because they require many small steps to stably advance the simulation forward in time. 

3. One of the main reasons that the presented system achieves higher speed than previous system is that it uses implicit method, modified conjugate gradient method to advance the simulation.

4. The presented simulation system couples a new technique for enforcing constraints on individual cloth particles with an implicit integration method. The simulator models cloth as a triangular mesh, with internal cloth forces derived using a simple continuum formulation that supports modeling operations such as local anisotropic stretch or compression; a unified treatment of damping forces is included as well. The implicit integration method generates a large, unbanded sparse linear system at each time step which is solved using a modified conjugate gradient method that simultaneously enforces particles' constraints. The constraints are always maintained exactly, independent of the number of conjugate gradient iterations, which is typically small.