# Why are these object passing through each other?

Okay, so as can be seen in the Gif below I have a scene in which I am trying to recreate a game like the “Tipping Point” game-show. The scene is made up of:
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• One box object with a collider to make up the backboard
• A number of cylinder object each with a collider to make the pegs
• One box object with collider and transparent material to make up front screen.
• A number of box objects with colliders to create the board and zone edges
• A box object with a collider and a script containing a mathf.pingpong function to make up the moving top shelf
• A box object with a collider to make up the static bottom shelf
• The Tokens, which are made with a pro-builder cylinder and collider and have a script which uses the addtorque and the addforce functions
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The problem is, as shown in the gif below, as when the token drops and hits the lower shelf it simply phases through the shelf, along with the rear-most one which begin on the top shelf. I don’t understand why the physics of this is having a problem. When I turn off the script which moves the top shelf the token falls and rests on the shelf with no phasing problem, so I can be sure that it has something to do with the moving platform. is there a better way to achieve the movement of the shelf which allows for better physics calculations?
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Unity Object “Phasing” Glitch Gif - link:Unity3D Object "Phasing" issue - Album on Imgur
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Thank you all in advance, I look forward to any help at all.
Kind Regards,
Cheyne

A box object with a collider and a script containing a mathf.pingpong function to make up the moving top shelf

Most likely the problem is here. Simply using a boxcollider and moving it’s transform won’t produce the expected physics effects in other rigidbodies.

In order for that setup to work the moving shelf must be a kinematic Rigidbody moved by calling Rigidbody.MovePosition() from FixedUpdate(). You can easily adapt your Mathf.PingPong-based code for that.