GPU Gems 2: Programming Techniques for High-Performance Graphics and General-Purpose Computation

Chapter 19. Generic Refraction Simulation

Tiago SousaCrytek

Refraction, the bending of light as it passes from a medium with one index of refraction to another (for example, from air to water, from air to glass, and so on), is challenging to achieve efficiently in real-time computer graphics. There are many well-known techniques for simulating light reflection (such as planar reflection maps and cubic environment maps), and these techniques work well in most situations. However, there aren’t as many widely known and effective techniques for simulating refraction. This chapter describes an approach to refraction based on perturbing the texture coordinates used in a texture lookup of an image of the nonrefractive objects in the scene. This technique ...