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Was doing a bit of work the other day and I was looking at collisions. Thinking about real collisions compared to ideal ones and the thing in particular which stands out is that often when two vehicles (for example) collide the striking vehicle will continue to travel some distance in its original direction. Thus I deduce it has retained some of its initial momentum both in size and direction.

Therefore the transfer of energy and momentum is not instantaneous, it is not instant and total. I deduce that it is due to crumpling and energy absorption rates of the vehicle's bodywork which causes this to happen.

So how would one go about modelling this non-ideal momentum transfer if one wanted to predict how two real vehicles would react when one hits the other? How do game programmers do it?

I would guess perhaps that a rough coefficient figure could be deduced depending upon where each vehicle was hit and the size and construction of the vehicle in question.

It struck me as a rather tricky situation. I've yet to figure out how to model the continuation of the initial vehicle doing the striking.

Perhaps if I can come up with a realistic means of modelling real momentum/energy transfer between the two vehicles then I could move each per unit time an appropriate amount depending on how the momentum had been shared between them.

If I used a small update time of say 10ms I could compute their new positions and rotations for each update time and then re-compute them for the next update time if they're still in contact with each other, given that any momentum vector associated with them would be stored in a dedicated variable.

I hope that makes some sense. I've got my mind into several things at the moment so I hope that doesn't sound like garbage

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# Momentum Exchange In Real Collisions

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