Arne Lakså, Børre Bang

Simulating rolling and colliding balls on free-form surfaces

We introduce an interactive REAL-TIME simulation of rolling balls on free-form parametric surfaces. The simulation includes solid and hollow balls with different size, moment of inertia, slip and rolling friction and collision detection and handling. We consider examples with several hundred balls of different types rolling and colliding on a free-form surface limited by a closed set of walls. We introduce a time discretization method which is a combination of a global nonuniform computation time depending time stepping, and a local nonuniform time discretization based on time sorted event handling. Finally we discuss some computational aspects. The examples are done on a standard workstation. We useC, OpenGL and GM_lib, an in-house geometric and graphic modeling library developed at Narvik University College.