Rendering diffuse objects using particle systems inside voxelized surface geometry

This paper presents an unique method for rendering complex shapes as fuzzy or diffuse objects inside virtual environments. It uses surface geometry that is converted into a voxel-like grid to specify the appearance of the shape. A particle system displays the outline of the object at runtime. Particles are allowed to move freely inside the voxel-grid but obtain certain attributes from the voxels they currently reside in. Those attributes assign color, size, textures, transparency to the particles, as well as forces that influence the movement of the particles. Force effects include linear and spiral movements, gravitational points, and helix-shaped motion of particles. Through this, complex movement of the particles inside the voxel-space can be created at interactive rates, while still maintaining the approximate form of the original surface geometry