[3.2] PhysicalBone inherited from RigidBody

[dedm0zaj]

Hello.
I changed the inheritance of the PhysicalBone through the RigidBody. Methods and properties are now available for the PhysicalBone such as add_force, add_torque, linear_velocity, etc.

Bugsquad edit: This closes godotengine/godot-proposals#1951.

[Calinou]

Thanks for opening a pull request 🙂

Pull requests (especially ones that break backwards compatibility) should be opened against the master branch instead of 3.2. This is because feature development occurs in the master branch. We can then cherry-pick specific PRs to the 3.2 branch if they don't break backwards compatibility.

[AndreaCatania]

Though, PhysicalBone is not a RigidBody even if they could seems to share some features.
The PhysicalBone has some mechanism that changes its collision model depending on some skeleton parameters; and subsequent RigidBody changes may break how the PhysicalBone works. But most important, under the hood, the physics engine can use a different technology to simulate a more precise and complex joint setup; which is generally used for ragdolls.

It's not yet implemented but implement it after this change would make things more difficult: #28909

I don't think it's desirable change it, even because we already have the methods apply_central_impulse (and similar) on the PhysicalBone; so if anything is missing on the PhysicalBone it's better add it.

[aaronfranke]

@dedm0zaj Is this still desired? If so, you should perform the above requested change, and remake this PR based on the master branch. Otherwise, this PR will be considered abandoned and closed.

[akien-mga]

This would break compat in the API so it can't be made in the 3.x branch, but it can be considered for master.