behaviac

Behaviac is an open-source behavior tree library developed by Tencent. It provides a visual editor and runtime library for creating and executing behavior trees, which are commonly used in game AI and other decision-making systems. The library supports multiple programming languages and platforms, making it versatile for various projects.

Pros

• Visual editor for easy behavior tree creation and modification
• Supports multiple programming languages (C++, C#, Java) and platforms
• Extensive documentation and examples available
• Includes features like blackboards, decorators, and parallel nodes

Cons

• Learning curve for those unfamiliar with behavior trees
• Visual editor is Windows-only, limiting cross-platform development
• Some users report occasional stability issues with the editor
• Limited community support compared to some other AI frameworks

Code Examples

1. Creating a simple behavior tree:

#include "behaviac/behaviac.h"

// Define a simple action
class SayHello : public behaviac::Action
{
    BEHAVIAC_DECLARE_DYNAMIC_TYPE("SayHello", behaviac::Action);

    virtual behaviac::EBTStatus execute(behaviac::Agent* pAgent)
    {
        printf("Hello, World!\n");
        return behaviac::BT_SUCCESS;
    }
};

// Create and run the behavior tree
behaviac::Workspace::GetInstance()->ExportMetas("../meta/");
behaviac::Workspace::GetInstance()->Load("../exported/SimpleBT");

behaviac::Agent* agent = behaviac::Agent::Create<behaviac::Agent>();
agent->btload("SimpleBT");
agent->btexec();

2. Using a decorator:

// Define a decorator that limits execution count
class LimitDecorator : public behaviac::DecoratorNode
{
    BEHAVIAC_DECLARE_DYNAMIC_TYPE("LimitDecorator", behaviac::DecoratorNode);

    int m_limit;
    int m_count;

public:
    LimitDecorator() : m_limit(3), m_count(0) {}

    virtual bool Evaluate(behaviac::Agent* pAgent)
    {
        return m_count < m_limit;
    }

    virtual behaviac::EBTStatus Update(behaviac::Agent* pAgent, behaviac::EBTStatus childStatus)
    {
        m_count++;
        return childStatus;
    }
};

3. Using a blackboard:

// Set and get values from the blackboard
behaviac::Agent* agent = behaviac::Agent::Create<behaviac::Agent>();
agent->SetVariable("health", 100);
int health = agent->GetVariable<int>("health");

Getting Started

1. Clone the repository:

   git clone https://github.com/Tencent/behaviac.git
   

2. Build the library and tools:

   cd behaviac
   mkdir build && cd build
   cmake ..
   make
   

3. Include the library in your project:

   #include "behaviac/behaviac.h"
   

4. Initialize behaviac in your main function:

   behaviac::Workspace::GetInstance()->ExportMetas("../meta/");
   behaviac::Workspace::GetInstance()->Load("../exported/YourBehaviorTree");
   

5. Create an agent and run the behavior tree:

   behaviac::Agent* agent = behaviac::Agent::Create<behaviac::Agent>();
   agent->btload("YourBehaviorTree");
   agent->btexec();