BehaveAsSakura

BehaveAsSakura is a behavior tree implementation for .NET and Unity. BehaveAsSakura provides several features to build multiplayer networking games with behavior trees easier.

Features

• Behavior trees are event-driven to avoid traversal of entire trees every frame and improve execution performance significantly.
• Traversal of trees and execution of tasks are deterministic which means simulations on client and server will give exactly the same result.
• Description of behavior tree is serialized with FlatBuffers so it is insanely fast to load trees into memory.
• Internal states of behavior trees are also serializable in case a full synchronization is necessary.
• A intuitive visual editor is provided in Unity with runtime debugging support.

Installation

.NET

Build the solution and copy assemblies under BehaveAsSakura\bin directory into your project.

Unity

Copy BehaveAsSakuraUnity\Assets\BehaveAsSakura directory into your Unity project.

Usage

Create a behavior tree description

A behavior tree description contains the tree structure of various tasks and description of tasks which are modifiable during runtime. There are two ways to create a behavior tree description.

One is create it with Unity Editor:

1. Create a behavior tree asset from menu Assets -> Create -> BehaveAsSakura Behavior Tree.
2. Select the new asset and it will open the editor window and custom inspector of tree description.
3. Right click on the entry node and select Create task -> Action -> Log in context menu.
4. Select the new task and it will open the custom inspector of task.
5. Edit the Message field and the behavior tree asset is saved automatically.

Another one is create a description from the fluent API.

// Build tree description via fluent API
var treeBuilder = new BehaviorTreeBuilder();
builder.Composite<SequenceTaskDesc>()
    .AppendChild(builder.Leaf<LogTaskDesc>(
        d => d.Message = "Start waiting"))
    .AppendChild(builder.Leaf<WaitTimerTaskDesc>(
        d => d.Time = new VariableDesc(VariableType.UInteger, VariableSource.LiteralConstant, "3000")))
    .AppendChild(builder.Leaf<LogTaskDesc>(d =>
        d.Message = "End waiting"));
var treeDesc = treeBuilder.Build();

// Write tree description into file
BehaviorTreeSerializer.Initialize(new FlatBuffersSerializer());
var bytes = BehaviorTreeSerializer.SerializeDesc(treeDesc);
File.WriteAllBytes("path/to/tree.bas", bytes);

Licensing

BehaveAsSakura is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.