Shadows indicate to the observer where light originates and helps convey the relative locations of objects in a scene. This chapter provides an introduction to the basic shadow mapping algorithm, which is a popular method for modeling dynamic shadows in games and 3D applications. For an introductory book, we focus only on the basic shadow mapping algorithm; more sophisticated shadowing techniques, such as cascading shadow maps [Engel06] which give better quality results, are built by extending the basic shadow mapping algorithm. Before we can discuss the shadow mapping algorithm, we must introduce two techniques the shadow mapping algorithm utilizes: render to texture and projective texturing.
To understand ...