Real-time deformable objects for collaborative virtual environments

This paper presents a method for physical simulation of deformable closed surfaces over a network, which is suitable for realistic interactions between users and objects in a collaborative virtual environment (CVE). CVE's are being extensively used for training, design and gaming for several years. To demonstrate a deformable object in a CVE, we employ a real-time physical simulation of a uniform-tension-membrane, based on linear finite-element-discretization of the surface yielding a sparse linear system of equations, which is solved using the Runge-Kutta Fehlberg method. The proposed method introduces an architecture that distributes the computational load of physical simulation between each participant. Our approach requires a uniform-mesh representation of the simulated structure; therefore we designed and implemented a re-meshing algorithm that converts irregularly triangulated genus zero surfaces into a uniform triangular mesh with regular connectivity. The strength of our approach comes from the subdivision methodology that enables to use multi-resolution surfaces for graphical representation, physical simulation, and network transmission, without compromising simulation accuracy and visual quality.