Relief mapping (computer graphics)

In computer graphics, relief mapping is an alternative texture mapping technique to parallax mapping that is much more accurate, and can support self-shadowing and normal mapping. It can be quite simply described as a short-distance raytrace done on a pixel shader; various techniques can be implemented to speed up the raytrace by taking variable step sizes.

Relief texture mapping supports the representation of 3D surface detail, producing self-occlusion, self-shadowing, view-motion parallax, and silhouettes. This technique produces correct views of 3D surfaces and scenes by augmenting textures with per texel depth.

It is not yet common in video games, as it is a rather slow technique due to the need for a large amount of per-pixel processing. Crysis, Oblivion, and Unreal Tournament 3 have a similar feature called Parallax mapping.

Recently Pamplona et al. published a new technique which animates relief impostors, billboards with normal mapping, displacement maps, or any other texture-based resolution-independent representation. 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 proposed technique preserves the relief-impostor properties, allowing the viewer to observe changes in occlusion and parallax during the animation. It can be used produce real-time realistic animations of live and moving objects undergoing repetitive motions.

See also

• Shaded relief, a cartographic technique that portrays terrain by using simulated shadows
• Bump mapping
• Normal mapping
• Parallax mapping

External links

• Relief mapping explanation, with code
• Manuel's Relief texture mapping
  • Real-Time Relief Mapping on Arbitrary Polygonal Surfaces
  • Relief Mapping of Non-Height-Field Surface Details