Simulation Levels of Detail for Real-time Animation

When sufficient computing power is available, dynamic simulation can be used as a source of motion for real-time, interactive virtual environments. In this paper, we explore techniques for reducing the computational cost of simulating groups of creatures by using less accurate simulations for individuals that are currently less important to the viewer or to the action in the virtual world. The less accurate, or lower level of detail, simulations can be dynamic with fewer degrees of freedom, hybrid kinematic/dynamic, or fully kinematic. We implemented a game that uses a dynamic simulation of a one-legged robot as the test creature. Because the creatures switch smoothly among different levels of detail for the underlying simulation, we can achieve real-time performance for a larger group of creatures than would be possible if each creature were fully dynamic. We assess the performance gain from using the simulation levels of detail and the effect that decreasing the accuracy of the simulations has on the outcome of the sample game