Collision Detector in Billiard

[krabbit]

Hi guys,
     this is my first post here. it's about quite months that i'm using java3d for a university project. We must realize a billiard game, 3d with java3d.
I lost my mind for days and days!!!!
Now i'm trying to understand howto get collision between balls working. i found some behaviour like CollisionDetector that have a processStimulus method, but i need to understand howto  get a relative position of balls, howto get the exact point of impact between two balls for later calculating new direction, etc....
Could u help me to find right way to develop my subject ? i tried to search some examples but  i don't find nothing to helpful and not so complex.
I have another problem: we don't have alot of time, about one month. Could u help me? thanx   Kr4b

[Breakfast]

If I were working on your project, I would approach it thus: I would separate the physics model from the 3D view entirely. If you think about it, everything in a game like billiards is working in 2D so it would be smart to create a 2D model of your table and balls and use that to calculate your collisions, trajectories and movement. I would tie it in to a simple 2D visual representation for testing.

I would then use that model to place my balls in my Java3D environment, so I would run a behaviour that ran every frame and just requested the current positions of the balls from the internal representation of the game and used that to set the x and z co-ordinates of the balls in the scene.

J3D doesn't have very good collision detection so this would be quicker and more accurate for this kind of project.

[Mr. Gol]

The standard collision detection that Java3D offers isn't what you want. Instead of collision detection you need collision avoidance, J3D.org has some good articles about that. Since it's a billiard game you may not even need that, since you can calculate everything if you have the positions and the radius of the balls. Circle/circle collision physics are quite hard, but I'm sure you can find some examples on the internet.

Games published by our own members! Check 'em out!

[otelo]

Circle/circle collision physics are quite hard...

Circle - circle collisions are hard? They are almost trivial compared to everything else! Breakfast's idea is very good in that respect,