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bakno
Up and Coming
October 16, 2016

Unity - Rift - Weird physics behavior

Unity 5.4. We have a game scene that relies on the physics engine to animate most of the objects. It is running fine on Desktop and sometimes fine on Oculus Rift. I will try to describe the problem:

When running on the Rift, the first time the scene is loaded, it works fine. Any further load of the same scene will have the problem, which seems to be a physics problem. 

Some objects which are stacked on top of each other in a stable position, are no longer stable and fall from the stack. Additionally, there is a pilot-bike arrangement (the main character) which reacts stronger to the controls. This particular behavior on the main character occurs on a regular scene (one that does not suffer from this problem) if we activate the Rigidbody Interpolation.

Initially we thought it was an overload problem. But we removed some heavy processes just to check and the problem persists. Additionally, as mentioned, the game runs fine on the first load, therefore it has to be related to a process that is activated by the VR classes.

We run a script that deactivates the character interpolation but it does not fix the problem either.

Please help
Andres
    This topic has been closed for replies.

    3 replies

    vrdaveb
    Inspiring
    October 16, 2016
    It sounds like you need to adjust your physics settings to stabilize activation and the constraint solver. PhysX can be counter-intuitive when it comes to objects waking up. Try increasing the solver iteration count and enable adaptive forces. If that doesn't help, maybe try increasing the sleep threshold and bounce threshold.
    baknoAuthor
    Up and Coming
    October 17, 2016
    Thank you @vrdaveb

    However, none of your suggestions worked. Not even changing all of them at the same time with exaggerated values.

    We are now able to replicate the problem within the Unity Editor. But so far we have not found the cause of the problem.

    It is strange how in regular mode it works fine, but when enabling VR, which basically just replaces de Camera, then the problem happens.

    And even stranger that the problem does not happen the first time the scene is loaded, but on all subsequent loads.
    baknoAuthor
    Up and Coming
    October 17, 2016
    After extensive trial and error, we found that the problem is not related to VR. Instead it is related to our gamepad control.
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