Strange Physics Problem

Unity Engine
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1

Hi,

I’m having a strange problem with the physics simulation and i’m hoping someone knows what could be wrong. I have 4 cubes stacked one on top of each other on a large box. The large box is a rigidbody and kinematic. The smaller stacked boxes are rigidbodies.

When I remove any box and let the rest drop on the larger box, most of the time they fall to rest on a side and all is normal, but other times they fall on a corner and freeze.

I read up on Rigidbody sleep, and i figured the ridigbody might be sleeping. I went and Sleep Velocity and Sleep Angular Velocity to 0, but the same thing happens.

I’m out of ideas, and not sure of how I can debug this situation.

Anyone have any clues?

Thank you very much,
Felix

2

I forgot to mention all my boxes have a Configurable Joint to restrict movement on the angular X and Y axis. (I’m building a 2d game and don’t need the boxes rotating in those directions)

Thanks

3

I’m guessing the configurable joint is your problem…remove it and just click “Freeze Rotation” on the rigidbody tab…hope this helps

4

Removing the configurable joint stops this problem, but i need the configurable joint to avoid the boxes from moving on the Z axis and rotating on the x and y axis. I’m building a 2d game andfound this the only way to restrict the movements.

Any ideas what could be causing this problem in the configurable joint.

Thanks!
Felix

5

OH! Now I understand what you’re doing!

I’ll look into this but this seems like a pretty specific problem…good luck

EDIT:
Are you getting this problem in the Editor/iPhone/both?

6

I’m getting this in both the iPhone and Editor. I’ve also noticed that if the box lands on an edge and stops, if i click on a field in the inspector without even changing anything the box falls flat!

Very strange.