In this gem, published in Game Programming Gems VII , the authors describe a new technique to animate relief impostors based on radial basis functions (RBF).
In a pre-processing step, the user specifies the animation using a set of correspondence points on the texture of the impostor. The animation is encoded using an RBF representation, which is saved into a texture. At runtime, the RBF texture is used to warp the relief texture on the GPU producing the desired animation.
The technique can animate relief impostors, billboards with normal mapping, displacement maps, or any other texture-based resolution-independent representation. All this is achieved with a simple RBF-evaluation shader function. The proposed technique can be used produce real-time realistic animations of live and moving objects undergoing repetitive motions.
This is the first technique to animate impostors with relief texture mapping.
 Vitor F. Pamplona, Manuel M. Oliveira, and Luciana P. Nedel. Animating Relief Impostors Using Radial Basis Functions Textures . In: Scott Jacobs (ed.) Game Programming Gems 7. Charles River Media, Inc., Hingham, Massachusetts, 2008, (ISBN-13: 978-1-58450-527-3). pp. 401-412.
Project Page: http://tinyurl.com/cmfgop