So I was intrigued by the concept of creating "realistic" collision damage to a bouncing or hit mesh. My first idea was to use ALL newton and somehow assign bones to points on a mesh. That seemed a lot of work and not very... flexible. So then I thought about using cloth. Portions of a mesh made of "stiff" cloth. It sort of worked but... dang... gravity and "inertia". It crushed nice on the first impact but then the "crushed" area would "reshape" when other collisions take place.
Still working on the technique but here's what I ended up as my first test:
Click to view attachment
I have the 8 corners as groups in a fairly dense box mesh. I assign the cloth material to one at a time and run the cloth sim in 8 separate chor actions (otherwise the sim "resets" the other corners each time it's run). After that I just hide all but one corner at a time and delete all the spline keys for each corner except when it hits the ground. This is a bit tedious but not that tedious. I should have included more patches in the corners or made the box more dense so the crush area isn't so "blocky".
This could be really cool using a dense larger surface and having it hit by something. It would deform the cloth pretty realistically maintaining the "shape" of the object that hits it, for example a car crash simulation or something like that. I would also like to simulate that fantastic "rippling metal" on the skin of the airplane in Superman Returns. When he catches the airplane in the ball field and the metal skin "ripples" down the surface? I know this could be done using hand animation and poses but I would love to "simulate" this using cloth and newton physics. It was such a cool little detail that blows your mind.
p.s. I think I could streamline the process by changing the "Use chor range" in the cloth sim. I could just figure out exactly where the collisions happen and only sim those frames. You have to do the newton sim first so I know where the hits are. Then it would only add keys in each chor action for that spot. The sim would run WAY faster (1 or 2 frames) and no need to delete the keys afterwards.