jschomay / elixir-behavior-tree

Elixir library for building AI's from composable behavior trees

Hi, I'm Jeff. I like to explore that special place where games, narrative, and AI intersect. I made the Elm Narrative Engine for making non-linear story games and lately I've been experimenting with generative AI in games.

Play Deadline Escape the subway before it is too late	Adding Inworld AI Characters to an Existing Game, Part 3: Reflections, Trust, and Pigeons What I learned from my players and my characters	Adding Inworld AI Characters to an Existing Game, Part 4: Going Deeper Getting the most out of AI chat bots	Getting Lost in the Forest Postmortem on Using AI Generative Tools to Create a Forest Maze Game

Follow on LinkedIn

Follow on Twitter

elixir-behavior-tree's Issues

Implementation of a parallel node

Hi,

I was wondering if with the current API it is possible to implement a parallel node.
I guess with a parallel you will end up with multiple active leaf nodes, end thus to signal fail/success the tree would need to accept some kind of identifier to mark the specific node that finished underneath the parallel.

  Node.parallel([:a, :b, :c])
  |> BehaviorTree.start()
  |> BehaviorTree.succeed(:b)

Currently the tree only accepts BehaviorTree.succeed/1 or BehaviorTree.fail/1.

Is there another way to achieve the parallel node with the current API ?

How to handle interruptions?

Hi, is there an idiomatic way to generate interruptions, as described in Petter Ögren's video https://youtu.be/DCZJUvTQV5Q?t=544 ?

Thanks!

[edit] I guess that making sure that "longer running actions are merely the repetition of smaller actions" (see https://gamedev.stackexchange.com/questions/114125/behavior-tree-with-interrupted-sequence) is the way ensure that conditions are evaluated often enough. Do you agree?

BehaviorTree.value returns unexpectedly a Node

To reproduce the issue:

tree = Node.sequence([
             Node.repeat_until_succeed(:wait),
             Node.repeat_until_succeed([
               Node.sequence([
                 :pose_question,
                 Node.repeat_until_fail(:evaluate_answer)
               ])
             ])
           ])

tree |> BehaviorTree.start |> BehaviorTree.fail |> BehaviorTree.value

returns:

[
  %BehaviorTree.Node{
    type: :sequence,
    children: [
      :pose_question,
      %BehaviorTree.Node{
        type: :repeat_until_fail,
        children: [:evaluate_answer],
        repeat_count: 1,
        repeat_total: 1,
        weights: []
      }
    ],
    repeat_count: 1,
    repeat_total: 1,
    weights: []
  }
]

but I was expecting :pose_question instead.

Is the tree malformed or am I missing anything?

Thanks!

running and error state?

Hi Jeff,
do you have any plan to add the running and error states?
Thanks!

The repeat_n behavior node does not work properly when nested.

When nesting one repeat_n behavior Node inside another the nested one only runs the first pass. After that the nested Node.repeat_n seems to be ignored.

To Reproduce:
Run the tree in the included zip file

Expected behavior:
Based on the attached tree there should be 5 "Create new membership" log entires for each "Get new pool" log entry.

Nested_Repeat.zip

Debug features: draw tree

It could be nice to get a visual representation of the tree at any given moment, including the current node.

Consider using graphviz format as a possible output.

This is such a cool project!

Just stopping by to say hi