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Parallax Occlusion Mapping with Soft Shadows. CSCI580: 3-D Graphics and Rendering. Bump Mapping. A Perturbation to the surface normal is looked up in a texture map. The change is then applied before the illumination calculation is done. Pros : Richer, more realistic and detailed surface
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Parallax Occlusion Mapping with Soft Shadows CSCI580: 3-D Graphics and Rendering
Bump Mapping • A Perturbation to the surface normal is looked up in a texture map. • The change is then applied before the illumination calculation is done. • Pros : Richer, more realistic and detailed surface • Cons : Does not exhibit parallax and self shadowing.
Normal Mapping • Illusion of bumps and dents without using a high number of polygons. • A 3 channel bitmap containing surface normal data is called a normal map. • The RGB channels of the map represent the X,Y,Z values of the normal vector. • These values are used as normals for a given pixel.
Parallax Mapping – An Introduction • Also known as offset mapping • An enhancement of the bump mapping or normal mapping techniques • Textures appear to have more depth and realism with less impact on performance. • Displays motion parallax.
Parallax Displacement δ View Ray Polygonal Surface (u’, v’) (u, v) 0.0 Input Texture coordinate Texture coordinate offset Result of Normal Mapping Extruded Surface Displaced point on surface 1.0
Soft Shadows • In the algorithm, we continue sampling the height field along the light ray past the first shadowing horizon • until we reach the next fully visible point on the surface. • Then we filter the resulting visibility samples to compute soft shadows with smooth edges.
Wikipedia - http://en.wikipedia.org/wiki/Parallax_mapping • GameDev.net - http://www.gamedev.net/columns/hardcore/pom/ • Practical Dynamic Parallax Occlusion Mapping by Natalya Tatarchuk - • http://ati.amd.com/developer/techreports/2005/SIGGRAPH2005/Tatarchuk-ParallaxOcclusionMapping-Sketch-SIG05-Slides.pdf • fxComposer by Nvidia • GamePipe Game Engine by GamePipe Labs, USC • http://www.bencloward.com/tutorials_normal_maps1.shtml References
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