Simple (and fast) dices physics
- by Markus von Broady
I'm programming a throw of 5 dices in Actionscript 3 + AwayPhysics (BulletPhysics port).
I had a lot of fun tweaking frictions, masses etc. and in the end I found best results with more physics ticks per frame. Currently I use 10 ticks per frame (1/60 s) and it's OK, though I see a difference in plus for 20 ticks.
Even though it's only 5 cubes (dices) in a box (or a floor with 3 walls really) I can't simulate 20 ticks in a frame and keep FPS at 60 on a medium-aged PC. That's why I decided to precompute frames for animation, finishing it in around 1700 ticks in 2 seconds. The flash player is freezed for these 2 seconds, and I'm afraid that this result will be more of a 5 seconds or even more, if I'll simulate multi-threading and compute frames in background of some other heavy processes and CPU drawing (dices is only a part of this game).
Because I want both players to see dices roll in same way, I can't compute physics when having free resources, and build a buffer for at least one throw of each type (where type is number of dices thrown). I'm afraid players will see a "preparing dices........." message too often and for too long.
I think the only solution to this problem is replacing PhysicsEngine with something simpler, or creating own physicsEngine. Do You have any formulas for cube-cube and cube-wall collision detection, and for calculating how their angular and linear velocities should change after a collision occurs?