For doors its just a matter of rotating them correctly. No need for actual physics joints. If the door is a separate CustomUnityAsset you can just use an AnimationPattern in VaM to animate (rotate) the door. If the door is part of a larger object (say a car) but still its own Unity GameObject, you can use a tiny script fo find door in the CustomUnityAsset and rotate it there. (See my SecretRoom environment for an example how to have a script modify something inside a CustomUnityAsset)