collider-material-binding#

Code

PMT.001

Validator

Compatibility

Tags

Summary#

Every collider (prim with PhysicsCollisionAPI) must have a material:binding:physics relationship to a physics material.

Description#

Physics materials define the surface properties that affect collision behavior, including friction, restitution, and density. For proper physics simulation, every collider must be bound to a physics material through the material:binding:physics relationship.

The material:binding:physics relationship connects a collider prim (with PhysicsCollisionAPI) to a physics material prim (with PhysicsMaterialAPI), enabling the simulation engine to apply the correct material properties during collision detection and response.

The material:binding:physics relationship is the recommended, explicit form. Because the physics binding purpose resolves with the standard USD fallback to the allPurpose material:binding, a collider that binds a physics material (with PhysicsMaterialAPI) through a plain material:binding relationship also satisfies this requirement. Validation resolves the bound material for the physics purpose and confirms it has PhysicsMaterialAPI applied.

Examples#

# Invalid: Collider without physics material binding
def Cube "MyCube" (
   prepend apiSchemas = ["PhysicsCollisionAPI"]
) {
   double size = 1.0
   # Missing material:binding:physics relationship
}

# Valid: Collider with physics material binding
def Cube "MyCube" (
   prepend apiSchemas = ["PhysicsCollisionAPI"]
) {
   double size = 1.0
   rel material:binding:physics = </Materials/Metal>
}

def Material "Metal" (
   prepend apiSchemas = ["PhysicsMaterialAPI"]
) {
   float physics:density = 2700
   float physics:dynamicFriction = 0.1
   float physics:restitution = 0.1
   float physics:staticFriction = 0.1
}

How to comply#

  1. Ensure every prim with PhysicsCollisionAPI has a material:binding:physics relationship

  2. The relationship must target a valid physics material prim (with PhysicsMaterialAPI)

  3. Physics materials should have appropriate values for density, friction, and restitution

  4. Use meaningful material names that reflect the intended physical properties

For More Information#