,Two Similar Rigidbodies with velocity behaving differently

Hello fellas,

This is my very post here so I apologize in advance for any mistakes or misuse of a tool.
I’m new to Unity and am trying to design a very simple game here. For the mechanics, the two key components are a rectangular pad and a cube.


They are both given the same initial velocity of 5f in the z-direction (to the right in the image)
Unless I either specify it on code (C#) or a collision with an obstacle occurs, I want the cube to maintain this velocity.

However, it seems like in some frames, its velocity rapidly decays and then comes back to the former velocity (this behaviour can be confirmed via console) and, eventually, the pad reaches the cube and also surpass it.

I’ve tried to solve this issue via Script Execution Order, exchanging Update with FixedUpdate and vice-versa, adding Physics Materials; all with no luck.

Important to highlight: I’m assuming the difference of functioning is due to the pad being a trigger and the cube is a collider (no “is trigger” marked). But with no friction, no drag nor angular drag, and constantly update via script, I expected the velocity to be constant.

Has anyone had the same issue and found a workaround? Am I missing something?

I don’t know the answer, just my opinions that might help somehow, hopefully.

  1. I can’t test if right now but I’m assuming you’re using Kinematic rigidbodies, right?
  2. Do you need to have rigidbodies? Whenever I need complete control over an event, I tend to do the math manually, like collision detection. Maybe you could achieve the same effect without them.
  3. Also does this happen on the builds as well? Maybe an Editor thing?
  4. What about the ground object, maybe it has friction. Did you try applying the same friction-less material to it as well?
  5. I’m sure you’ve tried testing it in a new project, assuming anything you might’ve changed in the Physics section would interfere here.