Using Texture Mapping Techniques to Simulate Lights and Shadows in Real Time Computer Graphics

Abstract

Texture mapping was born as a technique to add realism to a scene by wrapping a bitmap onto a polygon and making it appear as though the bitmap is going through the same transformations as the polygon. From then it has grown considerably. Today it is used to simulate things like shiny surfaces (environment mapping), rough surfaces (bump mapping) without adding any additional geometry. Recently, texture mapping has been used to simulate lights and to a certain extent shadows. The research here shows just how applicable texture mapping techniques are to simulating lights and shadows. This is done by using texture mapping techniques to replace a light in the scene by a light map and than showing that the scene is still illuminated in the same manner as with the conventional light. The research also investigates the effects of combining light maps and rotating the light maps. It also shows that the light map does improve performance of the Phong shading algorithm. In the area of shadows, the paper examines some of the most popular shadow casting algorithms and then implements a simple shadow casting algorithm to show how texture mapping can be used to cast shadows onto multi planar surfaces.

Participants

Technical Reports

[1] Melissa Ridderhof. Realistically rendering multiple lights. Technical Report Honours Project Report, Virtual Reality Special Interest Group, Computer Science Department, Rhodes University, Grahamstown, South Africa, November 2002. [HTML] [BibTeX]

[2] Tomasz Zaniewski. Using texture mapping techniques to simulate lights and shadows in real time computer graphics. Technical Report Honours Project Report, Virtual Reality Special Interest Group, Computer Science Department, Rhodes University, Grahamstown, South Africa, November 2000. [DOC] [PDF] [BibTeX]

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