With enough force, box collider goes through planes.

I made a grenade that rolls too much, so I decided to use a box collider. if an edge of the box hits the ground, it goes right through. And ideas?

If the wall is thin enough, and the force strong enough, it will pass through.

possible solutions:

  1. reinforce the wall, add an invisible cube collider behind it
  2. if that’s not enough, decrease the fixed timestep, but be carefull not to over do it )
  3. if all else fails, handle the “exception” manually in a FixedUpdate()

Planes are buggy like that.

If you give it a box collider, it should work better.

maybe when an object is close to another object you can switch it into continuous detect mode Unity - Scripting API: Rigidbody.collisionDetectionMode

Try moving the grenade on a FixedUpdate.

The reason it is moving through the planes and can move though other collider if because one frame the grenade is on one side of the collider and by the next frame it is already on the otherside, a simple fix is to change the collision detection mode to continuous. You can also mess with the physics calculation settings in project settings.