Collision Avoidance and Surface Flow for Particle Systems Using Distance/Normal Grid

Fire, explosions, and other special effects are often created with particle systems. In real-time applications the particle systems must be very fast to evaluate since otherwise the application cannot maintain reasonable frame rate. One part of this challenge is the collision detection between particles and the objects in the scene. We present a new approach to collision detection and surface flow effects for particle systems. In pre-processing phase we rasterize a 3D model into a distance/normal grid. The grid can be used for collision avoidance, to create surface drag and to simulate fluid flow around non-deforming objects. This method is not physically accurate, but it provides visually plausible results. The primary benefit of this method is that it is efficient and its performance is independent of the complexity of the model. This methods works well in real-time, in some cases surpassing the rendering speed of modern graphics hardware by order of magnitude.