This PR aims to separate model descriptions from instances. When a model description is changed, for instance its mesh or kinematic properties, all of its instances should also be changed. The user should also be able to change the description of an instance.
This PR aims to separate model descriptions from instances. When a model description is changed, for instance its mesh or kinematic properties, all of its instances should also be changed. The user should also be able to change the description of an instance.