Dynamic tire grip / ground materials behavior in Community Edition

Question

My goal is to dynamically change tire friction (Grip / μ) depending on the surface each wheel is touching, so that all 4 wheels can use different friction values simultaneously (e.g. left wheels on ice, right wheels on gravel).

I tried to use `VPGroundMaterialManager` based on the documentation and forum posts, but I cannot find the component.

Questions:

1. Is `VPGroundMaterialManager` available in Community Edition? If yes, how should it be configured?

2. If it is not included and requires custom implementation, is this understanding correct?

• attach a component derived from `VPGroundMaterialManager`
• vehicle model automatically calls `GetGroundMaterial()`
• each wheel independently receives the material of the collider it touches

Or is additional vehicle-side registration/setup required?

3. I understand Community Edition supports only one ground material ("asphalt"), but can its Grip / Drag values still be modified?

4. To achieve per-wheel dynamic friction behavior, are the only options either:

• upgrading to Professional Edition and using Ground Materials
• or modifying `VPVehicleController > Tires` values via script in Community Edition

Also, is my understanding correct that:

• Ground Materials = per-surface, per-wheel automatic behavior
• Tires settings = shared vehicle tire settings unless modified manually by script

Answer 1

1. No, VPGroundMaterialManager is not available in the Community Edition. In this edition, all ground materials have the same default properties.

2. Custom implementations are also unavailable in the CE, and this includes Ground Materials as well. These cannot be modified.

3. No, the unique ground material use only the default values for Grip and Drag.

4. You can modify the Tires values via script in the CE, but changes will affect the four wheels. Only the paid editions support modifying each wheel independently.

This is correct:

• Ground Materials = per-surface (collider), per-wheel automatic behavior
• Tires settings = shared vehicle tire settings, modifiable by script

Additionally, the paid editions support:

• Multiple ground materias. Each collider can have it's own grip and drag properties for tires.
• Modify each individual wheel's tire friction properties independently of the shared vehicle tire settings.
• Custom ground material managers. Instead of handling the ground material per collider, a custom manager could assign tire friction properties based on any other criteria, for example the combination of terrain maps at the wheel's contact point.