I'm somewhat new to map design, and was wondering how this person pulls of the broken concrete wall look while seamlessly blending it to the actual building. I see this a lot in treyarch maps, and this mappers level of detail is mind boggling to say the least.



Is this some sort of patching and then moving the vertices to make it appear jagged, or is this models / prefabs?

Any help would be greatly appreciated!! 

It could go either way as far as models or bsp.

There are a few good tutorials from the WAW days that will guide you through this process.

I noticed treyarch will use blend textures on small terrain patches to get the burnt look on top of bsp brushes. A lot can be achieved through csg subtracting and breaking up the bsp into small chunks to achieve this effect. BUT REMEMBER to always work inside prefabs when using csg subtract, else you will destroy all your zombiemode volumes ect and make a giant mess.