Nested FSM Support

[Yogeb-tech]

Hello!

I wanted to get your thoughts on a NestedFSM node I implemented. It derives from State and initializes a self-contained FSM that inherits values from the main FSM. Additionally I've also created a demo similar to the blacksmith demo to showcase this new functionality.

Looking ahead, I'm considering overloading the _on_enter, _on_process, and _on_exit functions to give users more control.
For example, in a fighting game, a "Crouching" nested FSM could use its _on_enter function to play the crouching animation. This ensures the animation plays before any sub-state (like "Crouch Jab") runs, eliminating the need to manually trigger it in every possible transition or every sub-state's on_enter function into the crouching posture.

Do you have any suggestions or concerns about this direction?

[ThePat02]

Yo! I already noticed you working on that. I will take a look later that week, as it is something I have been wanted to add for some time now, but the workaround of nesting a fsm inside a integrated behaviour tree was more comfortable (or less work).

Looking ahead, I'm considering overloading the _on_enter, _on_process, and _on_exit functions to give users more control.

What's the difference from overloading the state like you would normally? This is what you do with all states anyways, so I do not see why this would be a problem.

[Yogeb-tech]

I'm very glad to see you approve of this implementation! Hopefully I can get back to work on this now that I have more time on my hands. I plan to implement more robust transition checks for the Transition class. This would include generating warnings for cross-hierarchy transitions, such as when a nested FSM attempts to transition into an ancestor FSM.

Then after some clean up, comments, and a template I feel it should be finished.

[Yogeb-tech]

I'm just now realizing there is a lot more work than I thought to fully integrate NestedFSMs beyond adding configuration warnings for transitions into this plugin. I'm just going to continue working until I feel it's finished lol.

[Yogeb-tech]

Ok I think nested FSMs are in a good state.

• Added script templates where appropriate
• Added to the toolbox in the UI
• Added to the documentation
• Added a configuration warning to FSMTransition, that emits when a user selects a next transition state that is part of a outside of the FSM/NestedFSM's scope
  • The implementation is a bit shaky. I tried to keep it all self-contained in FSMTransition. I would like to see your feedback on it, perhaps I'm a bit paranoid.
• Added a configuration warning to NestedFSM, that emits when a user selects an initial state that is part of a different FSM/NestedFSM.
  • This was also added to FiniteStateMachine. I feel it's not out of the question people would run state machines in parallel

Any feedback is welcome!

[ThePat02]

I will do some testing and experimenting! Thanks for your addition! Looks good so far!