3D Collision dection and response

[starphoenix]

I am making the physics engine for a personal project, and one of the more important parts is that the collisions are detected and respond as accurately as possible. right now I'm in the preliminary phases of designing this, so I'm sticking to basic shapes, axis aligned boxes, axis aligned cylinders, and spheres.

The problem I'm coming across is I have found how to deal with a single point collision, and two point collision, if an edge of something collides with a surface. But the one case I have not been able to at all figure out how to deal with, is if two surfaces completely collide with each other. IE if two boxes hit each other head on, the two faces will both smack right into each other.

Anyone know how to resolve these kinds of collisions? Should I just compute a point that is at the center of the colliding faces and treat it as a single point collision? Ideally I would like this to include angular motion as well, but at this point in time I am only dealing with linear motion.

Thanks in advance guys!

 

[morongo]

You may have already seen this, but here's the link in any case:

http://www.gamedev.net/reference/articles/article736.asp

 

[ravenprp]

One possible solution for handling collisions between two surfaces is to use a technique called Separating Axis Theorem (SAT). This involves projecting the two objects onto different axes and checking for overlaps. If there is an overlap on all axes, then a collision has occurred and you can calculate the collision response.

Another approach is to use a technique called Continuous Collision Detection (CCD), which involves continuously checking for collisions during the movement of objects. This can help prevent objects from passing through each other, especially in high-speed scenarios.

In terms of angular motion, you can apply the same principles of SAT and CCD to calculate the angular velocity and rotation of the objects after a collision.

It's also important to consider the shape of the objects being used. For example, if your objects have curved surfaces, you may need to use a different collision detection algorithm such as GJK or EPA.

Overall, it's important to carefully consider the specific needs of your project and choose the most appropriate collision detection and response techniques. There are many resources available online and in books that can provide more in-depth explanations and examples. Good luck with your physics engine!