The 4 wheels on my custom vehicle do not collide with the ground mesh, despite being properly placed and set up according to this tutorial: How to Set up Vehicles in Unreal Engine | Unreal Engine 5.2 Documentation
This seems like a common issue, however, there doesn’t seem to be a clear answer on the possible causes.
- Some mention colliders: which I removed from the template’s example car, and it continues to work fine, due to the correct PhysX Wheels setup.
- Others mention that the joints are set up poorly, but my joints were tested and exported through Maya, by someone who has done actual rigging, so perhaps I imported it poorly?
I have uploaded the project I’m working: ue4_wheelchair.zip - Google Drive
It includes the FBX for the “vehicle” I use. It might be more complicated, due to the differently sized wheels.
Currently Simulating or running the level, will have the vehicle glitch through the floor. Use CMD (~) > PXVIS COLLISION command to debug draw the PhysX wheel for testing (the level BP will do this for you).
Also of note, I enabled a custom gravity value to have the vehicle slowly drop onto the ground plane.
My theory is that the joints’ root node has an inverted UP-axis, which encourages the physics engine to resolve the collision with the ground plane, by pushing it downwards, which it expects is the opposite of the gravity vector, which it is not, I suppose.
Any suggestions are much appreciated!