Projective texture mapping

Projective texture mapping is a method of texture mapping described by Segal [3] that allows the texture image to be projected onto the scene as if by a slide projector. Figure 1 shows some example screen shots from the projspot demo, available in the NVIDIA OpenGL SDK. Projective texture mapping is useful in a variety of lighting techniques, including shadow mapping [4]. This document provides some background and describes the steps involved in projective texture mapping in OpenGL.