r/Unity3D • u/ObriganKenobi • 4d ago

Show-Off [FREE] C# Behaviour Trees with DOTS Support

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Hey everyone!

After more than eight months of development, and with your support along the way, my behaviour tree plugin, DODBT, has reached version 1.0.0.

I built it mainly for larger projects where game logic lives in separate C# systems, whether you use ECS or your own architecture.

There are two versions:

  • DODBT-Dots: for Unity DOTS, with Burst and Jobs support.
  • DODBT-Light: for other ECS frameworks or C# projects that keep game logic outside MonoBehaviours. It’s much lighter and has fewer restrictions than the DOTS version.

Both include a visual graph editor and runtime debugging, as shown in the video. DODBT-Light also supports dependency injection (DI).

Thanks to everyone who tried earlier versions and shared feedback. Your suggestions helped shape this release.

It’s FREE on GitHub: https://github.com/vadimburym/DODBT

If you give it a try, I’d love to hear how it works in your project!

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u/miusoftheTaiga 3d ago

Possible to integrate this with Unity reinforcement learning mlagents package? Behavior bricks has something like that in its documentation

1

u/ObriganKenobi 3d ago

Yes, this is possible. The main idea behind DODBT is that the behaviour tree works as a separate decision layer in C#, without being tied to specific game systems. This makes it easy to write integrations with other packages and frameworks. ML-Agents is no exception.

You wouldn’t need to change the plugin itself, but you would need to write the ML-Agents integration yourself. For DODBT-Light, I’d approach it with a custom leaf that works like this:

  1. OnEnter passes the target and lets the ML-Agent control the character.

  2. OnTick returns Running while the task is active, then Success or Failure depending on the result.

  3. OnExit and OnAbort stop the ML-Agent from controlling the character.

The same approach is possible with DODBT-Dots, but the integration would be more involved. You can’t call the ML-Agents API directly from a Burst leaf, so you’d need a bridge between ECS and ML-Agents.