For the past couple years when talking to chip makers about new 3D features, 3D texture maps would always come up, and I would have to mutter something like: “I think it is a good thing, but I can’t give you a really awesome example of using it. 3D Noise functions. Stuff like that.”
I have the awesome example now: Lighting.
Through the entire development of Q3, I have been wanting to do dynamic lighting of the world differently. Many of the efficiencies gained by Q3′s new map format result in larger and larger lightmaps while it reduces polygon count. That meant that even small dynamic lights may force a lot of work to generate new lighting textures.
He also has posted his worklog again which is, as usual, very interesting to read so I suggest you check it out.