The RBD Car deform SOP deforms high-res car geometry after simulating the proxy car geometry. This can be used to add details such as tire compression against the ground geometry, deforming suspension components, and controlling which geometry inside the tires should be rotated.

• The first input takes your output geometry from the simulation (where the car ended up driving to).

• The second input takes the original rest geometry (first output from your car rig).

• The third input takes any custom collision geometry that you're bringing into the bullet solver as a heightfield. This will take into account the proper collision surface when doing tire deformation to compress the wheels.

The Ground Plane will use the same values as the RBD Bullet Solver, so there’s no need to set everything up again. If you don’t see compression on the tires, you may have to adjust the Wheel Scale on your RBD Car Rig. The scale is automatically generated to fit the wheel geometry, so you may need to scale this down when doing tire deformations. Scaling this value lower will allow the tire to penetrate with the ground a little and the RBD Car Deform will push them back up creating a tire bulge where it touches the ground.

The Neighbor Distance controls how struts are setup internally to preserve volume. The value represents the number of edges between the two end points of each surface strut constraint. Higher distances produce larger wrinkles, but also create more constraints that take more time and memory to solve.

Deforming suspensions has pretty good default values and works well out of the box. However, if you want to make changes you can change the Mode from Tires to Suspensions in the Operation Controls menu located along the top of the viewport. This will provide you with controls to edit the suspensions in the viewer state.