Fluid Behavior Tree - Code Driven Behavior Trees

Fluid Behavior Tree is a code driven Unity behavior tree library for Unity. It's easily extendable and utilizes the builder pattern.

Feature Highlights

• Unity Package Manager friendly
• No 3rd party plugins
• 140 unit tests and growing for good code coverage
• Pre-built library of tasks to kickstart your AI
• Tracks the last position of your behavior tree and restores it the next frame
• Built for Unity (works as soon as you install it)
• Code base is easily extendable to add your own custom nodes

Behavior Tree Example

Code (CSharp):

1. using UnityEngine;
2. using CleverCrow.Fluid.BTs.Tasks;
3. using CleverCrow.Fluid.BTs.Trees;
4.  
5. public class MyCustomAi : MonoBehaviour {
6.     private BehaviorTree _tree;
7.  
8.     private void Awake () {
9.         _tree = new BehaviorTreeBuilder(gameObject)
10.             .Sequence()
11.                 .Condition("Custom Condition", () => {
12.                     return true;
13.                 })
14.                 .Do("Custom Action", () => {
15.                     return TaskStatus.Success;
16.                 })
17.             .End()
18.             .Build();
19.     }
20.  
21.     private void Update () {
22.         // Update our tree every frame
23.         _tree.Tick();
24.     }
25. }

Extending Behavior Trees

Code (CSharp):

1. using UnityEngine;
2. using CleverCrow.Fluid.BTs.Tasks;
3. using CleverCrow.Fluid.BTs.Tasks.Actions;
4. using CleverCrow.Fluid.BTs.Trees;
5.  
6. public class CustomAction : ActionBase {
7.     protected override TaskStatus OnUpdate () {
8.         Debug.Log(Owner.name);
9.         return TaskStatus.Success;
10.     }
11. }
12.  
13. public static class BehaviorTreeBuilderExtensions {
14.     public static BehaviorTreeBuilder CustomAction (this BehaviorTreeBuilder builder, string name = "My Action") {
15.         return builder.AddNode(new CustomAction { Name = name });
16.     }
17. }
18.  
19. public class ExampleUsage : MonoBehaviour {
20.     public void Awake () {
21.         var bt = new BehaviorTreeBuilder(gameObject)
22.             .Sequence()
23.                 .CustomAction()
24.             .End();
25.     }
26. }

If you have questions or need help getting started feel free to post here. You can also join us on Discord. Source code available at GitHub.

 

thanks, great job

 

Great BehaviorTree for unity3d! Please add support for ScriptableObject.

 

Hi!
Can you tell what unity version suit for each version of Fluid Behavior Tree?
for example, i use unity2018.4.18, which Fluid Behavior Tree version is best fit?

 

Hi!
I import it into project with package manager, it is easy to install, but when i change the folder name of my project and open again, it said path not find. How can i change the path to relative path?

Thank you!

 

@unicoea oh hey, I usually do support requests on Discord or through the GitHub issues page. Ping me there and I can help. I find these things require quite a bit of back and forth to debug sometimes.