The pictures are mostly environmental shots, meant to demonstrate how id Tech 5 technology can create "unique, very large textures." As you can see from the screenshots, there are some very large textures indeed.
If you're technically minded and fascinated by these things, you can access id's Tech 5 demonstration materials in this handy PDF. The rest of you can go back to believing in the magic graphic faeries that make videogames appear out of pixie dust.
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