Rigid Body Offset
By default, the position and spatial orientation of a Rigid Body is defined by its Point Controllers:
But in real-life scenarios mass might not be distributed so evenly.
Here, for example, the majority of the mass is concentraited at the head, while the handle only amounts for a small part of it. Logically, the corresponding Rigid Body should be placed at the head.
But on the other hand, we’d still want to keep the Point Controllers where they are so it would be convenient to animate:
For cases like these, we can use Rigid Body Offset.
2. After this, proto components will become visible in the Outliner:
Every proto component (ProtoUnion_Pelvis_int in this example) has a prototype rigid body (ProtoRigidBody_Pelvis_int in the example) attached to it.
3. Select this rigid body in the Outliner.
This way you can adjust Rigid Bodies to more precisely represent the distribution of mass.
Adjusted positions of the prototype Rigid Bodies are saved in the .casc files, as well as in the JSON files used for interchanging rig data.