Accurate Collision Detection and Impact Physics Calculations

Questions & Answers
1

Hello everyone, I am making a boxing game using Unity 3D and the Kinect. Currently I am using rigidbodies, triggers, and a little math to handle collisions and force. I am using Unity’s built in collision detection for my sphere collider (hands) and a box collider for my target (enemies). Every update tick, I am recording the current position and time. Then, whenever a collision is triggered, I am using the new position, old position, and elapsed time to determine the velocity. I am then using the velocity and mass to calculate my force and am applying as an impulse force to my target. Here are my two issues:

  1. How do I improve the accuracy of my collision detection? Sometimes my hand travels through my enemy. I am using the Kinect, so my hands can move pretty fast. Not much else is going on in this game, so there isn’t much processing needed in other parts.

  2. How can I improve the quality of my impact physics? Currently my mass is an arbitrary “1”, and the scale of my arms (in game distance) is unknown. Is there a better way to calculate impact force?

2

You can edit how accurate collision detection is the Edit>Project Settings>Physics Menu. That should be all you need to tweak, increasing the the accuracy too much will cause lag.