Out of interest, while 3dsmax has W-information editable and available on models (UVW editor - you can move things forward/back through W-space as well as the regular UV), Maya only allows editing of UV coordinates, indeed it doesn't even seem to have a concept of W-depth for UVs. I guess you can't do this sort of stuff in…
In graphics-programmer-talk 3D textures are a lot like voxels actually. You can think of it as a stack of 2D textures and the w texture coordinate (u,v,w) picks which layer of the stack is sampled by u and v. 3D textures are primarily used in procedural effects like "Perlin Marble" or "Terrible Wood Shader" as found in…