US Patent 7385603 Method for simulating motion of cloth

A method for simulating motion of cloth or other flexible membranes corrects surface-to-surface intersection involving a membrane. The method may be applied at time intervals of a conventional motion simulation for computer-generated animation. When a collision is detected, a function for a line of intersection between intersecting surfaces is parameterized in terms of vertices of the membrane model. The function is differentiated, and a correction factor is applied to the dynamic simulation in proportion to the value of the partial derivative for respected ones of the intersected vertices. The correction factor may be smoothed over a number of vertices in the vicinity of the intersected vertices.