Yes, for dynamic bodies this works. But for Kinematic bodies it has no effect, because their mass is “infinite”. In Box2D you can move Kinematic bodies with SetLinearVelocity, which allows natural interaction with dynamic objects. A typical example for this is a moving platform in a platform game.
That mean’s kinematic body isn’t movable with physics (colliding doesn’t count)?
What if I want player to be a tire (from movie Rubber ) and I want it to move by physically rolling?
As far as I’ve tried physics in Gamemaker it had all Box2d api, so that seems weird that defold doesn’t have.
I like the feature, but I think we would need to have a design meeting and think about how it would impact other systems (ways of updating the positions etc). I don’t think I can answer any more specific than that, part because I’m not an expert on the physics internals.
Adding an issue for this so we can discuss it internally: #4170
Code only. You will have to setup some interaction between game objects and the extension. Plus at first not all functionality will be available, but people will be able to modify and extend the extension.