Function AnimationNodeStateMachineTransition.advanceCondition
Turn on auto advance when this condition is set. The provided name will become a boolean parameter on the AnimationTree that can be controlled from code (see url=https://docs.godotengine.org/en/latest/tutorials/animation/animation_tree.html#controlling-from-code/url). For example, if AnimationTree is an AnimationNodeStateMachine and advanceCondition is set to "idle":
$animation_tree"parameters/conditions/idle" = is_on_floor and (linear_velocity.x == 0)