Automatic Texture Coordinate Generation on Radeon®

Figure 1 - Texture fogging Figure 2 - Linear texture mapping   Figure 3 - Projective texture Figure 4 - Diffuse lighting   Figure 5 - Sphere environment mapping Figure 6 - Cubic environment mapping

Using automatic texture coordinate generation with hardware support provides benefits of significant reduction of bandwith required for geometry data, and off-loading texture coordinate computation from processor to dedicated graphics hardware. Also, automatic texture coordinate generation is a rich source of various visual effects. RadeonTexGen sample illustrates some of the techniques achievable with automatic texture coordinate generation: Texture fog (Figure.1) This type of fog allows developer to implement fog using look-up table stored as a texture. The position in the look-up table is calculated as a vertex position in camera-space. Linear texture mapping (Figure.2) Texture coordinates can be calculated as a linear function of a model-space position providing an ideal solution for texture mapping onto planar surfaces such as floors, walls and etc. Texture transform matrix needs to be defined to transform from camera-space to model-space coordinates. Projective texture (Figure.3) For detailed explanation on projective texture mapping see Projective Texture Mapping Tutorial in Radeon® SDK. Diffuse lighting (Figure.4) Automatic texture coordinate generation can be used to perform diffuse and specular lighting. To implement diffuse lighting, camera-space normals transformed into the world space can be used for mapping into lightmap. Sphere and cubic environment mapping (Figure.5,6) Texture coordinate generation for environment mapping can be automatically performed by dedicated hardware using camera-space normals for sphere environment mapping and camera-space reflection vectors for cubic environment mapping.

RadeonTexGen Controls A, T, S- Change model 1 - Texure fog mode 2 - Linear texture mapping 3 - Projective texture mapping 4 - Diffuse lighting demo 5 - Sphere environment mapping 6 - Cubic environment mapping [SPACE] - Advance Frame-by-frame [ENTER] - stop advancing Frame-by-frame [ESC] - Quit

Downloads

Note: The source code and media should be unzipped into the following recommended directory structure to ensure you can easily compile and run the executable. Radeonxxxxxx.zip -> x:\atiddk\Direct3D\Radeonxxxxxx media.zip -> x:\atiddk\media RadeonTexGen.zip media.zip Back to Samples Page