AnimationTree: travelling directly to a state inside a SubStateMachine doesn't work, even though the transition is valid.

[eh-jogos]

Godot version

4.0.alpha10

System information

Manjaro Linux, Nvidia proprietary drivers, Vulkan Clustered

Issue description

So this is the animation tree for my beat em up character

I added the hurt and knockout states today, and it made a whole mess of it, since you can go from any ground state to any hurt state and from almost any state to knockout_launch.

I was trying to see if I could organize or do this in a better way, as I still have more attacks and grab/throws to add, when I noticed we can now add transitions directly to another state inside an AnimationNodeStateMachine! Wonderfull! In fact I had not done jump as an AnimationNodeStateMachine because I needed to be able to go to the "falling" state at any time, but now that I know I can create transitions directly to it, I was able to reorganize my AnimationTree like this:

Much better!

But when I tried to code the transitions, it doesn't work.
If, for example, I do:

_playback.travel("attack_group/attack1")

I get:

E 0:00:00:0569   _travel: Condition "!p_state_machine->states.has(p_travel)" is true. Returning: false
  <C++ Source>   scene/animation/animation_node_state_machine.cpp:179 @ _travel()

(link to github source I got from right clickig error)

Even though this:

var state_machine = _animation_tree.tree_root["nodes/state_machine/node"] as AnimationNodeStateMachine
var value = state_machine.has_transition("idle", "attack_group/attack1")
_playback.travel("attack_group/attack1")
print("value: %s"%[value])

prints true:

So when I ask AnimationNodeStateMachine if the transition is valid through GDScript, I get a true, but apparently the AnimationNodeStateMachinePlayback can't find it.

If needed I can provide prints from the "child" state machines or from the transitions in the inspector, I was just trying to not spam the description with even more images.

Steps to reproduce

Use the MRP below, or:

1. Create a Scene with at least two animations
2. Create an AnimationTree with a AnimationNodeStateMachine as root
3. Add one animation directly and another inside a new AnimationNodeStateMachine
4. Connect the outside animation directly to the inside animation
5. Try to travel to it.

Minimal reproduction project

broken_animation_tree.zip

The default scene has everything set up, just run it and use the arrow keys to try to play different animations

Only ui_right and ui_down will work, as they are transitions between the "idle" state and the "move_group" state, both which are on the same AnimationNodeStateMachine.

ui_up and ui_left which are transitions from "idle" directly to AnimationNodeAnimations inside the "move_group" AnimationNodeStateMachine, will not work, even though they'll print that the transition is valid (when you are coming from idle)

[guilhermefelipecgs]

At the moment travel only works for states in the same state machine. I think I can change that. I'll take a look.

[eh-jogos]

@Calinou Shouldn't this be tagged as 4.0? As connections to states inside another AnimationNodeStateMachine are not available on 3.x (at least up to 3.4), and this is only a bug if I can make this connections in the editor but not travel to them in runtime.

[eh-jogos]

@TokageItLab just noticed this was moved to 4.x, wouldn't it be better to remove the UI that allows for connecting a state node directly to a child state node of another state machine? I mean, if I can't travel to it, why can I connect it?

Or is this a problem only when trying to use travel from code, but if you use conditions for auto-traveling it works?

[TokageItLab]

cc @SaracenOne @guilhermefelipecgs