Advanced Texturing: Stupid Texture Tricks

1. Advanced Texturing:Stupid Texture Tricks David Luebke University of Virginia

2. Recap • A point sprite is a screen-aligned textured quad placed by rendering a single vertex • A billboardis a textured (usually) quad that (usually) rotates to face the viewer • Performer demo, Far Cry demo • Billboard clouds • An imposter is a billboard created on the fly to “cache” rendered imagery • Sometimes also refers to just a textured LOD

3. Recap • A depth texture affects and is affected by the depth buffer • NV_DEPTH_TEXTURE demo

4. Imposters Continued • Depth meshes • UNC MMR system • Imposters for urban environments

5. Billboards cont. • Can represent an entire object with just billboards! • Common trick for trees • Billboard clouds apply idea to other (all) objects • Trick is to compute these automatically…

6. Multitexturing • Modern hardware can read from multiple textures at once, even with mipmapping • Detail texturing • Light mapping • Bump mapping

7. Textures:Other Important Stuff • Render to texture • Environment maps • Simplest approach: sphere map • Hardware supports cube maps • Shadow maps • Basically, a depth texture from the point of view of a light source • More later

8. Textures:Still More Stuff • Normal maps • Gloss maps, reflectance maps, etc • Generally: • Think of textures as global memory for fragment programs, w/ built-in filtering • Soon (next-gen hardware) will be able to access textures in vertex programs too • Deferred shading • Projective texture mapping

9. Next topic: Cg • Many of the tricks we discuss in this class do not depend on programmable graphics hardware • But, most are easier to implement this way! • So, the next topic is a brief intro to Cg • My apologies to those of you who’ve seen this • My apologies to those of you who haven’t.