First, you can see the bug in action here: https://www.youtube.com/watch?v=vqbo3rweEmA

When rigidbody objects are falling from high position (300 in my test), the ground collision doesn't works, the objects falls through ground.

As you can see in the video, when I change the height to 30, it works.

The spheres have rigidbodies using gravity and a sphere collider. For info, the grounds have mesh collider for the two on the right, and a box collider for the one on the left.

I've tried to add kinematics rigidbodies to the grounds but it doesn't changes anything.

Using Unity 2020.3.28f1.

You can find a minimal reproduction here: https://github.com/BenDevelopment/Unity-3D-gravity-collision-bug

Any idea why the collision behave like this?

  • 1
    \$\begingroup\$ Looks like a classic case of tunneling... Try to make your objects thicker. \$\endgroup\$
    – Vaillancourt
    Mar 6, 2022 at 11:03
  • 1
    \$\begingroup\$ Alternatively, you can play around with collision detection mode for RigidBodies. \$\endgroup\$
    – liggiorgio
    Mar 6, 2022 at 12:15
  • \$\begingroup\$ @liggiorgio and Vaillancourt: I think together those two comments are the correct answer to this question. Would one of you like to post this as an Answer below? Or would you propose closing this question as a duplicate of past Q&A about physics tunnelling? \$\endgroup\$
    – DMGregory
    Mar 6, 2022 at 12:42


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