Wheeled vehicle wheels freely rotating on wrong axis

Development Character & Animation
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1

I created a skeletal mesh for a wheeled vehicle. I followed the rigging instructions in the Vehicle Art Setup page (). Now, inside the Physics Asset for the skeletal mesh, when I click Simulate the vehicle spins in circles as the wheels freely rotate under the vehicle. It’s as if the wheels were round spheres, and not attached to the car.

Here’s a video of the car doing pirouettes:

Is this a problem with the rig? It has a root joint, and one joint at each tire’s center. Are there constraints that need to be placed on the joints in Maya prior to the mesh being exported?

Any help would be greatly appreciated. Thank you.

2

Its because you have not set any limits for the joints. Put the PhAT editor on constraint mode so you can edit joints. Then select 4 joints that connects wheels to the body (Use CTRL for multiselect). Then in angular limits section:

Angular Swing 1Motion: Locked

Angular Twist Motion: Locked

Angular Swing 2Motion: Free

You are basically limiting joint rotation to only one axis.

For more info watch this:
https://docs.unrealengine.com/latest/INT/Videos/Player/index.html?series=PLZlv_N0_O1gaHlJrP4F12Px7ceHw3PDq-