Compound textures for dynamic impostor rendering

Impostors can be used as an alternative representation of distant objects in complex 3D scenes. They work by replacing the distant object with a simple texture map. Although this texture map must be updated as the viewpoint moves around the scene, it is not necessary to do this every frame. The saving inherent in not completely rendering the entire scene for every frame means that using impostors can significantly improve frame rate. One of the main challenges presented by the implementation of such a rendering algorithm is the capture, organisation and tracking of the impostor textures needed for every object. This paper explores some ways of doing this using OpenGL in ways that make the best use of current consumer level graphics hardware.