Run code for each AnimationTree state machine transition

[timokoesters]

I would like to use AnimationTree state machines as the single source of truth for my character state. For example, when the player presses jump, the AnimationTree changes from idle to jumping, triggering code to set an upward velocity. The player should go to idle again, when he hits the ground later.

However, when I do this, then the animation tree changes from idle to jumping, but then immediately back to idle, because the player is still on the ground.

I would like to run code for each state transition, potentially running multiple times per frame and potentially enabling or disabling other transitions.