I did this CG roof, in entirely in 3DSMAX, to the Video Clip, of a very popular Brazillian Rock Band, called RODOX. I take some pics with my digital cam, and work on them to do the textures. The CG Roof, needs to colapse on the Video Clip. I did the animation, using tons of (Dust) particles and a bit of compositing. The roof needs to have the same look of the real Scenario, on the clip. No special renders used. (Don't have time to wait for hours of rendering...), so i fake the like (fakeosity), and it works fine on the screen.