Continuous collision detection not working

Questions & Answers
1

I have a very simple scene with a fast moving ball going straight towards a cube. The ball is set to have continuous dynamic collision. The collision isn’t calling OnTrigger() when the ball is at high speed. Is this a bug or am I doing something wrong?

Here is the exact setup:

  • a kinematic cube with box collider at (0,0,0) set to trigger and no rigid body

  • a sphere with sphere collider at (0,251,0) with ball collider and rigid body with no gravity set to continuous dynamic

  • a script sets the velocity of the ball to (0,-100,0) in Start()

  • another script tells me if the OnTrigger is called

The OnTrigger() does not get called. I know my setup is correct because if I set the velocity to (0,-20,0) instead of (0,-100,0) everything works as expected.

2

Changing Project Settings>Time>Fixed Timestep from 0.02 to 0.01 fixes the issue. However this seems like a bug with Unity. With a Timestep of 0.01001 the issue is still there, but with 0.01000001 the issue is not there.