What exactly is it? Can anybody explain to me for what reason surfaces have to be tesselated?
I'd be really interested in this as tesselation is what keeps me from using small texture scales (= more polygons). Other engines, such as q3 for example don't seem to have tesselation or anything similar as, when showing wireframe ingame, even the biggest walls with the smallest texture scales on them only consist of two polygons instead of hundreds. Any ideas?

Cheers