How to get collision volume?

I want to make the physics of a low pressure tire like on all-terrain vehicles.

To simulate such a tire, I want its collider to always fall into the ground and the more the tire volume falls through, the stronger the pushing up force. In order to calculate pushing up force, each frame I need to calculate how much the tire volume fell into the ground. So how i can get the volume of a collision?

Two things:

  • I am pretty sure that the force of a car is not define by the amount of volume of the wheel inside the ground, but the amount in contact with it.
  • If you did not know, Unity provide a pretty decent package to simulate vehicles. You may want to start with it before trying to implement anything yourself.

If you really want to calculate the volume, you will need to do it manually. Alternatively, you can create multiple small collider on the tire and look how many are “under” the ground.