Migration from legacy PhysicsSchema

General:
- all attributes are prefixed with physics, so say density is now physics:density attribute
- apiName removes physics prefix, so GetDensity is still used
- PhysicsSchemaPhysicsScene is now UsdPhysicsScene etc
- units:
  - units respect metersPerUnit
  - all dimensional angular values are specified in degrees
PhysicsSchemaAPI and PhysicsSchemaMultipleAPI and its custom Unapply removed - use native UsdPrim::RemoveAPI function instead.
PhysicsScene:
- rename PhysicsSchemaPhysicsScene to UsdPhysicsScene
- gravity replaced by gravityDirection and gravityMagnitude default values can be used now, default direction (0,0,0) will pick the current -UpAxis default magnitude -inf will pick earth gravity based on metersPerUnit
- invertCollisionGroupFilter was moved to PhysxPhysicsScene
PhysicsAPI:
- rename to UsdPhysicsRigidBodyAPI
- CreatePhysicsEnabledAttr rename to CreateRigidBodyEnabledAttr
- bodyType - removed, was not used
- PhysxRigidBodyAPI::wakeOnStart replaced by UsdPhysicsRigidBodyAPI::physics::startsAsleep
- new attributes physics::velocity and physics::angularVelocity - VelocityAPI was removed
- angularVelocity is in degrees
- velocity is in world space used by omni.physx, there will be a flag to turn on local space as thats the default behavior to have velocity in a local space
VelocityAPI:
- removed use UsdPhysicsRigidBodyAPI::physics::velocity and UsdPhysicsRigidBodyAPI::physics::angularVelocity instead
MassPI:
- rename to UsdPhysicsMassAPI
- mass attribute changed to float
- density attribute changed to float, density now respects metersPerUnit so a density 1000 when stage is in meters is 0.001 when a stage is in cm
- centerOfMass attribute changed from double3 to point3f
- diagonalTensor attribute changed from double3 to float3, inertia respects metersPerUnit now, the units are mass*distance*distance
- principalAxes attribute changed from quatd to quatf
CollisionAPI:
- rename to UsdPhysicsCollisionAPI
- physicsMaterial rel removed, use material binding instead. There is a helper function for that in physicsUtils.py def add_physics_material_to_prim(stage, prim, materialPath): bindingAPI = UsdShade.MaterialBindingAPI.Apply(prim) materialPrim = UsdShade.Material(stage.GetPrimAtPath(materialPath)) bindingAPI.Bind(materialPrim, UsdShade.Tokens.weakerThanDescendants, "physics")
- collisionGroup rel removed, use collection:colliders that automatically applied to a UsdPhysicsCollisionGroup. Colliders that belong a certain collision group are now defined through the collection on a collisionGroup.
PhysxMeshCollisionAPI::approximation was replaced by UsdPhysicsMeshCollisionAPI
- use UsdPhysicsMeshCollisionAPI::approximation to define the mesh approximation
PhysicsMaterialAPI:
- density attribute changed from double to float, density now respects metersPerUnit so a density 1000 when stage is in meters is 0.001 when a stage is in cm
CollisionGroup:
- rename to UsdPhysicsCollisionGroup
- does have automatically UsdCollection:colliders applied, this collection holds the colliders that belong to that group
FilteringPairsAPI:
- rename to UsdPhysicsFilteredPairsAPI
Plane:
- moved to PhysxSchemaPlane
PhysicsJoint:
- localPos0, localPos1 changed from float3 to point3f
- jointFriction - was never used, so got removed
- added excludeFromArticulation that defines whether a joint should be excluded from an articulation, maximalJoint can be defined through this
- breakForce uses metersPerUnits - mass * distance / time / time
- breakTorque uses metersPerUnits - mass * distance * distance / time / time
RevolutePhysicsJoint:
- rename to UsdPhysicsRevoluteJoint
- lowerLimit - units in degree now
- upperLimit - units in degree now
PrismaticPhysicsJoint:
- rename to UsdPhysicsPrismaticJoint
SphericalPhysicsJoint:
- rename to UsdPhysicsSphericalJoint
- coneAngle0Limit - units in degree now
- coneAngle1Limit - units in degree now
DistancePhysicsJoint:
- rename to UsdPhysicsDistanceJoint
FixedPhysicsJoint:
- rename to UsdPhysicsFixedJoint
LimitAPI:
- rename to UsdPhysicsLimitAPI
- low - in degree or distance
- high - in degree or distance
DriveAPI:
- rename to UsdPhysicsDriveAPI
- maxForce - units: linear drive: mass*DIST_UNITS/time/time angular drive: mass*DIST_UNITS*DIST_UNITS/time/time
- targetType was removed instead its possible to set both targetPosition and targetVelocity through separate attributes.
- targetPosition/targetVelocity for angular drive in degree
ArticulationAPI:
ArticulationJointAPI:
- both were removed and ArticulationRootAPI has been introduced.
- fixed articulations should have ArticulationRootAPI on a root joint that is connected to world or in the hierarchy above the joint
- floating articulations should have ArticulationRootAPI on a body where articulation starts on in a hierarchy above.