I have the following problem: The levels in my game are made up of a Large Quantity of small Models and because of that I am experiencing frame rate problems. I already did some research and came to the conclusion that the amount of draw calls I am making must be the root of my problems.

I've looked around for a while now and couldn't quite find a satisfying solution. I can't cull any of those models, in a worst case scenario there could be 1000 of them visible at the same time.

I also looked at Hardware geometry Instancing, but I don't think that's quite what I'm looking for, because the level consists of a lot of different parts.

So, what I'd like to do is combining 100 or 200 of these Models into a single large one and draw it as a whole 'chunk'. The whole geometry is static so it wouldn't have to be changed after combining, but different parts of it would have to use different textures (I think I can accomplish that with a texture atlas). But I have no idea how to to that, so does anybody have any suggestions?