USD collision in 5.4

Development Pipeline & Plugins
4

In 5.4

If you want to add collision you need to add the good schemas to your prim and then the token physics:approximation value and the physics:collisionEnabled boolean

over "pCylinder380" (
            prepend apiSchemas = ["PhysicsCollisionAPI", "PhysicsMeshCollisionAPI"]
        )
        {
            uniform token physics:approximation = "boundingCube"
            bool physics:collisionEnabled = 1

approximations values are
image

If you want to use another mesh as your collision mesh :

  • Meshes that represent collision shapes should be sibling from rendering mesh
  • These meshes should have the “guide” purpose
  • These meshes must use the “PhysicsCollisionAPI”, “PhysicsMeshCollisionAPI”. They should also use the none approximation
 def Mesh "Duck" (
        prepend apiSchemas = ["PhysicsCollisionAPI", "PhysicsMeshCollisionAPI"]
        prepend references = @Assets/Game/USD/Duck.usda@
    )
    {
        token visibility = "inherited"
        matrix4d xformOp:transform = ( (1, -0, 0, 0), (0, 1, -0, 0), (0, 0, 1, 0), (-80, -150, 20, 1) )
        uniform token[] xformOpOrder = ["xformOp:transform"]
    }

    def Mesh "Box" (
        prepend apiSchemas = ["PhysicsCollisionAPI", "PhysicsMeshCollisionAPI"]
        prepend references = @Assets/Game/Box.usda@
    )
    {
        token visibility = "inherited"
        matrix4d xformOp:transform = ( (1, -0, 0, 0), (0, 1, -0, 0), (0, 0, 1, 0), (-70, -150, 20, 1) )
        uniform token[] xformOpOrder = ["xformOp:transform"]
        uniform token purpose = "guide"
        uniform token physics:approximation = "none"
    }

    def Mesh "Sphere" (
        prepend apiSchemas = ["PhysicsCollisionAPI", "PhysicsMeshCollisionAPI"]
        prepend references = @Assets/Game/Sphere.usda@
    )
    {
        token visibility = "inherited"
        matrix4d xformOp:transform = ( (1, -0, 0, 0), (0, 1, -0, 0), (0, 0, 1, 0), (-50, -150, 100, 1) )
        uniform token[] xformOpOrder = ["xformOp:transform"]
        uniform token purpose = "guide"
        uniform token physics:approximation = "none"
    }

The cube and sphere will be used as collision meshes for the duck