I'm a student on my final year at uni on a game programming course and was thinking about doing my dissertation on the subject of collision detection. So far on my course we've dealt with collision detection in a very simple manor and for my dissertation I was thinking of doing some kind of comparison of collision detection systems in games for non-rigid bodies. I've looked at some of the plethora of articles on the subject of collision detection and found them to be quite bewildering, which I may be able to deal with as they are primarily aimed at simulations not games. I am looking to find out how collision detection is done in modern commercial games and also if a method of implementing a program that takes different collision detection systems that "plug in" is in any way feasible? I am skeptic about this myself as from what I’ve heard games tailor their collision detection systems based on the requirements of each individual game to save on processing. Given this fact a “plug in” collision detection system probably wouldn’t be very useful for professional games, if at all feasible. Thanks to anyone who replies in advance, M. Dabiri

You mentioned non-rigid bodies. Do you mean collision detection between deforming or deformable shapes? AFAIK that's fairly uncommon in games currently (although collision detection using articulated characters is not uncommon).

Anyway, perhaps you could clarify further exactly what sort of collision detection you're interested in.

Thanks for your reply,

Well, I was curious to see if collision detection of deformabla shapes is handled in games at all - and you have answered that for me.

But my main area of concern is collision detection for constantly changing objects in games, however they are done (be it multiple models,using articulated characters or... ) and the methods used in deriving accurate results for these collisions.

[Edited by - mdabiri on October 6, 2006 5:28:17 AM]

Quote:Original post by mdabiri
Well, I was curious to see if collision detection of deformabla shapes is handled in games at all - and you have answered that for me.

Well, don't take my word for it - it's just my observation that it's not yet commonplace in games.

I have seen at least a couple games though based on collision detection and physics simulation using deformable bodies. One was a 2D side-scroller where your character is a blob, essentially, that responds realistically to collisions, compression, and so on. I think maybe there was a similarly-themed 3D game in the 'announcements' forum fairly recently (although I'm not sure). So it is done; it's just not nearly as commonplace as using rigid bodies and/or articulated figures exclusively.

Quote:Original post by speciesUnknown
Can anybody reccommend an open source detection engine which can do the above things, using ray based collision? I've used collision detection engines which only detect intersection and they are not good enough for my purposes, since bullets almost always fly right through a mesh without touching it.

At the risk of hijacking the thread I'll mention that it's very common in games to handle bullets and other similar projectiles differently than other objects, for the reasons you mention. Specifically, projectile collision detection is often handled as a ray-tracing problem. That way, a discrete system can be used for the other objects in the game without having to worry about tunneling.

This is a great tutorial with complete sourcecode included: Polycolly by Olivier Rebellion