# Multiple collisions within a single frame cycle?

So say you want to simulate several objects in two dimensions, just bouncing around in a finite space. Using AABB and sweep tests, it shouldn't be that complicated to calculate single collisions between objects. But if you want to have an object bounce off another surface in the same frame (one collision), how do you account for any additional collisions after that first one? This might not make much sense, so I put a little graphic together to explain what I mean.

So say all this is happening in one frame cycle. The gray box moves up and bounces off the wall on the top; that's easy enough. That orange box is the problem, though. How do I calculate that collision as well (where the two translucent boxes are)? OR, if the frame rate is high enough, does it even matter? Thanks!

• No time to write a full answer, but this might help or at least contain useful reference literature: Cohen, Lin, Manocha, Ponamgi "Interactive and Exact Collision Detection for MultiBody Environments" (1994) Aug 22, 2012 at 13:46
• Is this an actual problem you are experiencing? Aug 22, 2012 at 16:53
• @MartinSojka - Thanks! Just took a quick breeze through that, it looks cool. I'll give it a more in-depth read when I get the chance. Aug 22, 2012 at 17:49
• @NoobsArePeople2 - Not a problem at the moment, but more of a concern. I'm slowly clunking along on some collision handling code and it struck me as something worth investigating before I put everything together. Aug 22, 2012 at 17:49
• @ChrisLangford In that case, I wouldn't rule this out as a problem that potentially might occur at some point. That said I wouldn't worry about it too much, instead focus on getting your system up and running. Then test and test and test to see a) if you can make this happen and b) if it does happen is the situation within the bounds of your application (i.e., under enough strain most (all?) systems will buckle and break but that point might not matter for your purposes). Aug 22, 2012 at 18:42