Need help - Smoke on impact of building collapse

If I had a building that collapses, and I wanted a smoke simulation on an impact with a weight paint, how would I go around doing this? I tried giving the building both a canvas AND brush, but that didn’t work. In addition, how would I make it so the building is the smoke FLOW and COLLISION? The smoke has to be able to have physical interaction with the building for the project. Thanks. (:

I would start with careful use of editing; present the collapse using multiple shots. This would let you plant smoke-emitters that would gush-out smoke and you could also then choose which frames of the rendered footage show the best smoke. Compositing would also give you flexibility. _(You can add lots of volume to smoke by layering multiple overlapping pieces of even the same smoke, slightly offset in time, if you have footage that consists only of that smoke. Cheap trick and it works great. Fiddling with the frame-rates makes it even more complex, with zero added computational cost, because smoke is naturally chaotic.)

Generally, you’d start with an establishing shot that shows the beginning of the collapse, then closer shots from several angles (all at “a safe distance” to be believable) which show details. Then cut back out to the pile of rubble. The physics-sim would give you the footage but you wouldn’t actually show all of it. The impression would be that several people were filming it from different places with their iPhones, and then someone cut it together. (And, none of the onlookers got killed.)

What I wouldn’t do is to simply have a fixed camera that shows the sequence from beginning to end, and I would avoid asking the smoke to actually “interact with” the debris. With everything else that’s already going on in the frame, I just don’t think that would be necessary. Usually when you film a falling building there’s some amount of foreground which can be used to hide things – you don’t have an entirely unobstructed point of view.

Thanks for the reply! Though, in all honesty, I really don’t want to have to create illusions to make it look like a good simulation. I want the good simulation to be a good simulation. That’s why I want to learn more advanced techniques in performing smoke sims whilst a fracture simulation is occuring at the same time. Thanks.