# PhysX 3.2.2: Vehicle.. wobbles around and moves uncontrolled

**URL:** <https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612>\
**Category:** Physics Modeling (closed)\
**Created:** [December 8, 2012, 10:12pm UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612 "2012-12-08T22:12:50Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Lunatix](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/lunatix/32/12169_2.png) [@Lunatix](https://forums.developer.nvidia.com/u/Lunatix)\
**Post date:** [December 8, 2012, 10:12pm UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612/1 "2012-12-08T22:12:50Z")

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Hi!

I’m trying to implement the vehiclesdk into my framework, i’m nearly finished with the vehicle - but it moves uncontrolled around and jitters/wobbles… shaking? I don’t know which word is correct \>\_\<  
I have no idea from what these behavior comes, i triple checked my vehicle against the vehicle sample from the sdk, i think i have done mostly the same. Maybe somebody has a hint for me or another sample or… something that helps :(

Also, it looks like the wheels are very static, it doesn’t looks like the suspension in the sample, but the values are equal… but i call the VehicleSuspension function and the updates function after that…

Has someone a hint or a solution?

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**Author:** ![jaworekplay](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@jaworekplay](https://forums.developer.nvidia.com/u/jaworekplay)\
**Post date:** [December 9, 2012, 3:46pm UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612/2 "2012-12-09T15:46:06Z")

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Hi Lunatix!  
If you could provide some code to which we could relate to, it would make helping a lot easier. Without knowing the code I would expect some functions being called twice, initialized with wrong values or have wrong values passed.  
That’s what I can say for now. If you can get us some samples, then we could help some more.  
Good luck.

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**Author:** ![Lunatix](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/lunatix/32/12169_2.png) [@Lunatix](https://forums.developer.nvidia.com/u/Lunatix)\
**Post date:** [December 10, 2012, 11:23am UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612/3 "2012-12-10T11:23:39Z")

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I finally figured it out: My chassis where where rotated by the 3d modeller, so i transformed the localpose of the chassis shape (-90°, -90°, 90°) - when i corrected the vertices at loading time and left the shape as Matrix.Identity, the behavior was as it should be :)  
Only thing now is, that the wheels are spinning very fast but don’t get much grip…

Is this a PxMaterial thing? But in the vehicle sample, the materials of the terrain are as mine on a plane (0.5f, 0.5f, 0.2f). My tires have “0.8f, 0.8f, 0.2f” and the chassis has “0.5f, 0.5f, 0.2f”. Engine has enough power, vehicle mass is around 1400 and the gravity is -9.81f… also, things are falling a bit slowly o\_o

Any suggestions?

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**Author:** ![Lunatix](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/lunatix/32/12169_2.png) [@Lunatix](https://forums.developer.nvidia.com/u/Lunatix)\
**Post date:** [December 10, 2012, 2:37pm UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612/4 "2012-12-10T14:37:30Z")

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So, i figured this out, too.  
Vehicle was to big and i had to correct some values… its almost not perfect now,  
but that will be a bit more finetuning.

Thanks for trying to help, jaworekplay :)

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**Author:** ![MikePhysX](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/mikephysx/32/14043_2.png) [@MikePhysX](https://forums.developer.nvidia.com/u/MikePhysX)\
**Post date:** [December 19, 2012, 5:31pm UTC](https://forums.developer.nvidia.com/t/physx-3-2-2-vehicle-wobbles-around-and-moves-uncontrolled/27612/5 "2012-12-19T17:31:14Z")

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Hi,

Sorry for the difficult time with the vehicle controller, we are working on API and tools improvements to make tuning easier in a future version of the SDK.

Thanks,  
Mike