you should definatley use projection mapping to get the original plate on there as a reference as dann said. You will never be able to seamlessly match it if you don't. As for your explosion fake it, you don't need to model each brick invdividually just give the impression. So model a few bits of debris to throw around, cut up your original geo etc.

Also you need to remember what's going to appear once the dust has settled? what's behind the bricks? you will need to paint another projection map of the destroyed building to go in behind.


Alan