If [code]true[/code], the body is deactivated when there is no movement, so it will not take part in the simulation until it is awaken by an external force.
This is multiplied by the global 3D gravity setting found in [b]Project > Project Settings > Physics > 3d[/b] to produce the body's gravity. For example, a value of 1 will be normal gravity, 2 will apply double gravity, and 0.5 will apply half gravity to this object.
If [code]true[/code], the RigidBody3D will not calculate forces and will act as a static body while there is no movement. It will wake up when forces are applied through other collisions or when the [code]apply_impulse[/code] method is used.
If [code]true[/code], the body is deactivated when there is no movement, so it will not take part in the simulation until it is awaken by an external force.