Modeling Liquids and Solids using Thermal Particles

This paper presents a new method for modeling fluids and solids for the purposes of computer graphics and animation. The model, based on molecular and Newtonian dynamics, describes the changes in geometry and movement of elemental volumes as a consequence of thermal energy and external forces . At "hot" temperatures objects exhibit fluid-like behavior with rapidly varying geometry. At "cold" temperatures objects behave like solids, retaining a stable shape but capable of deformation given sufficient external forces. To accommodate the cont.inual changes in topology, we use particles to represent elemental volumes with potential energies defined between pairs of particles. The shape of the potential energy function is varied as a function of temperature. The objects simulated by these particle systems exhibit varying degrees of rigidity. We present a physically-based animation in a simulated world where a particle based object changes thermal states while interacting with external forces and obstacles.