行为树的设计与实现

时间：2014-05-04 20:58:01 阅读：707 评论：0 收藏：0 [点我收藏+]

原地址：http://blog.csdn.net/luyuncsd123/article/details/18351137

查阅了一些行为树资料，目前最主要是参考了这篇文章，看完后感觉行为树实乃强大，绝对是替代状态机的不二之选。但从理论看起来很简单的行为树，真正着手起来却发现很多细节无从下手。

总结起来，就是：

1、行为树只是单纯的一棵决策树，还是决策+控制树。为了防止不必要的麻烦，我目前设计成单纯的决策树。

2、什么时候执行行为树的问题，也就是行为树的Tick问题，是在条件变化的时候执行一次，还是只要对象激活，就在Update里面一直Tick。前者明显很节省开销，但那样设计的最终结果可能是最后陷入事件发送的泥潭中。那么一直Tick可能是最简单的办法，于是就引下面出新的问题。目前采用了一直Tick的办法。

3、基本上可以明显节点有 Composite Node、Decorator Node、Condition Node、Action Node，但具体细节就很头疼。比如组合节点里的Sequence Node。这个节点是不是在每个Tick周期都从头迭代一次子节点，还是记录正在运行的子节点。每次都迭代子节点，就感觉开销有点大。记录运行节点就会出现条件冗余问题，具体后面再讨论。目前采用保存当前运行节点的办法。

4、条件节点（Condition Node）的位置问题。看到很多设计都是条件节点在最后才进行判断，而实际上，如果把条件放在组合节点处，就可以有效短路判断，不再往下迭代。于是我就采用了这种方法。

设计开始

在Google Code上看到的某个行为树框架，用的是抽象类做节点。考虑到C#不能多继承，抽象类可能会导致某些时候会很棘手，所以还是用接口。虽然目前还未发现接口的好处。

在进行抽象设计的时候，接口的纯粹性虽然看起来更加清晰，不过有时候遇到需要重复使用某些类函数的时候就挺麻烦，让人感觉有点不利于复用。

[csharp] view plain copy

public enum RunStatus  
{  
    Completed,  
    Failure,  
    Running,  
}  
  
public interface IBehaviourTreeNode  
{  
    RunStatus status { get; set; }  
    string nodeName { get; set; }  
    bool Enter(object input);  
    bool Leave(object input);  
    bool Tick(object input, object output);  
    RenderableNode renderNode { get; set; }  
    IBehaviourTreeNode parent { get; set; }  
    IBehaviourTreeNode Clone();  
}  
  
/************************************************************************/  
/* 组合结点                                                             */  
/************************************************************************/  
public interface ICompositeNode : IBehaviourTreeNode  
{  
    void AddNode(IBehaviourTreeNode node);  
    void RemoveNode(IBehaviourTreeNode node);  
    bool HasNode(IBehaviourTreeNode node);  
  
    void AddCondition(IConditionNode node);  
    void RemoveCondition(IConditionNode node);  
    bool HasCondition(IConditionNode node);  
  
    ArrayList nodeList { get; }  
    ArrayList conditionList { get; }  
}  
  
/************************************************************************/  
/* 选择节点                                                             */  
/************************************************************************/  
public interface ISelectorNode : ICompositeNode  
{  
  
}  
  
/************************************************************************/  
/*顺序节点                                                              */  
/************************************************************************/  
public interface ISequenceNode : ICompositeNode  
{  
  
}  
  
/************************************************************************/  
/* 平行(并列)节点                                                             */  
/************************************************************************/  
public interface IParallelNode : ICompositeNode  
{  
  
}  
  
//////////////////////////////////////////////////////////////////////////  
  
/************************************************************************/  
/* 装饰结点                                                             */  
/************************************************************************/  
public interface IDecoratorNode : IBehaviourTreeNode  
{  
  
}  
  
/************************************************************************/  
/* 条件节点                                                             */  
/************************************************************************/  
public interface IConditionNode  
{  
    string nodeName { get; set; }  
    bool ExternalCondition();  
}  
  
/************************************************************************/  
/* 行为节点                                                             */  
/************************************************************************/  
public interface IActionNode : IBehaviourTreeNode  
{  
  
}  
  
public interface IBehaviourTree  
{  
      
}

View Code

很多节点的接口都是空的，目前唯一的作用就是用于类型判断，很可能在最后也没有什么实际的作用，搞不好就是所谓的过度设计。如果最终确定没有用再删掉吧。

接口里出现了一个渲染节点，目的是为了能够更方便的把这个节点和负责渲染的节点联系到一起，方便节点的可视化。

如果只有接口，每次实现接口都要重复做很多工作，为了利用面向对象的复用特性，就来实现一些父类

[csharp] view plain copy

public class BaseNode  
{  
    public BaseNode() { nodeName_ = this.GetType().Name + "\n"; }  
  
    protected RunStatus status_ = RunStatus.Completed;  
    protected string nodeName_;  
    protected RenderableNode renderNode_;  
    protected IBehaviourTreeNode parent_;  
  
    public virtual RunStatus status { get { return status_; } set { status_ = value; } }  
    public virtual string nodeName { get { return nodeName_; } set { nodeName_ = value; } }  
    public virtual RenderableNode renderNode { get { return renderNode_; } set { renderNode_ = value; } }  
    public virtual IBehaviourTreeNode parent { get { return parent_; } set { parent_ = value; } }  
    public virtual IBehaviourTreeNode Clone() {  
        var clone = new BaseNode();  
        clone.status_ = status_;  
        clone.nodeName_ = nodeName_;  
        clone.renderNode_ = renderNode_;  
        clone.parent_ = parent_;  
        return clone as IBehaviourTreeNode;  
    }  
}  
  
public class BaseActionNode : IActionNode  
{  
    public BaseActionNode() { nodeName_ = this.GetType().Name + "\n"; }  
    protected RunStatus status_ = RunStatus.Completed;  
    protected string nodeName_;  
    protected RenderableNode renderNode_;  
    protected IBehaviourTreeNode parent_;  
    public virtual RunStatus status { get { return status_; } set { status_ = value; } }  
    public virtual string nodeName { get { return nodeName_; } set { nodeName_ = value; } }  
    public virtual RenderableNode renderNode { get { return renderNode_; } set { renderNode_ = value; } }  
    public virtual IBehaviourTreeNode parent { get { return parent_; } set { parent_ = value; } }  
    public virtual IBehaviourTreeNode Clone()  
    {  
        var clone = new BaseActionNode();  
        clone.status_ = status_;  
        clone.nodeName_ = nodeName_;  
        clone.renderNode_ = renderNode_;  
        clone.parent_ = parent_;  
        return clone as IBehaviourTreeNode;  
    }  
  
    public virtual bool Enter(object input)  
    {  
        status_ = RunStatus.Running;  
        return true;  
    }  
  
    public virtual bool Leave(object input)  
    {  
        status_ = RunStatus.Completed;  
        return true;  
    }  
  
    public virtual bool Tick(object input, object output)  
    {  
        return true;  
    }  
}  
public class BaseCondictionNode {  
    protected string nodeName_;  
    public virtual string nodeName { get { return nodeName_; } set { nodeName_ = value; } }  
    public BaseCondictionNode() { nodeName_ = this.GetType().Name+"\n"; }  
    public delegate bool ExternalFunc();  
    protected ExternalFunc externalFunc;  
    public static ExternalFunc GetExternalFunc(BaseCondictionNode node) {  
        return node.externalFunc;  
    }  
}  
  
public class Precondition : BaseCondictionNode, IConditionNode{  
    public Precondition(ExternalFunc func) { externalFunc = func; }  
    public Precondition(BaseCondictionNode pre) { externalFunc = BaseCondictionNode.GetExternalFunc(pre); }  
    public bool ExternalCondition()  
    {  
        if (externalFunc != null) return externalFunc();  
        else return false;  
    }  
}  
  
public class PreconditionNOT : BaseCondictionNode, IConditionNode  
{  
    public PreconditionNOT(ExternalFunc func) { externalFunc = func; }  
    public PreconditionNOT(BaseCondictionNode pre) { externalFunc = BaseCondictionNode.GetExternalFunc(pre); }  
    public bool ExternalCondition()  
    {  
        if (externalFunc != null) return !externalFunc();  
        else return false;  
    }  
}  
  
public class BaseCompositeNode : BaseNode{  
    protected ArrayList nodeList_ = new ArrayList();  
    protected ArrayList conditionList_ = new ArrayList();  
    protected int runningNodeIndex = 0;  
    protected bool CheckNodeAndCondition() {  
        if (nodeList_.Count == 0)  
        {  
            status_ = RunStatus.Failure;  
            Debug.Log("SequenceNode has no node!");  
            return false;  
        }  
        return CheckCondition();  
    }  
    protected bool CheckCondition() {  
        foreach (var node in conditionList_)  
        {  
            var condiction = node as IConditionNode;  
            if (!condiction.ExternalCondition())  
                return false;  
        }  
        return true;  
    }  
    public virtual void AddNode(IBehaviourTreeNode node) { node.parent = (IBehaviourTreeNode)this; nodeList_.Add(node); }  
    public virtual void RemoveNode(IBehaviourTreeNode node) { nodeList_.Remove(node); }  
    public virtual bool HasNode(IBehaviourTreeNode node) { return nodeList_.Contains(node); }  
  
    public virtual void AddCondition(IConditionNode node) { conditionList_.Add(node); }  
    public virtual void RemoveCondition(IConditionNode node) { conditionList_.Remove(node); }  
    public virtual bool HasCondition(IConditionNode node) { return conditionList_.Contains(node); }  
  
    public virtual ArrayList nodeList { get { return nodeList_; } }  
    public virtual ArrayList conditionList { get { return conditionList_; } }  
  
    public override IBehaviourTreeNode Clone()  
    {  
        var clone = base.Clone() as BaseCompositeNode;  
        clone.nodeList_.AddRange(nodeList_);  
        clone.conditionList_.AddRange(conditionList_);  
        clone.runningNodeIndex = runningNodeIndex;  
        return clone as IBehaviourTreeNode;  
    }  
}

View Code

然后实现具体的节点，先是序列节点

[csharp] view plain copy

public class SequenceNode : BaseCompositeNode, ISequenceNode  
{  
    public SequenceNode(bool canContinue_ = false) { canContinue = canContinue_; }  
    public bool canContinue = false;  
  
  
    public bool Enter(object input)  
    {  
        var checkOk = CheckNodeAndCondition();  
        if (!checkOk) return false;  
        var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
        checkOk = runningNode.Enter(input);  
        if (!checkOk) return false;  
        status_ = RunStatus.Running;  
        return true;  
    }  
  
    public bool Leave(object input)  
    {  
        if (nodeList_.Count == 0)  
        {  
            status_ = RunStatus.Failure;  
            Debug.Log("SequenceNode has no node!");  
            return false;  
        }  
        var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
        runningNode.Leave(input);  
        if (canContinue)  
        {  
            runningNodeIndex++;  
            runningNodeIndex %= nodeList_.Count;  
        }  
        status_ = RunStatus.Completed;  
        return true;  
    }  
  
    public bool Tick(object input, object output)  
    {  
        if (status_ == RunStatus.Failure) return false;  
        if (status_ == RunStatus.Completed) return true;  
          
        var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
        var checkOk = CheckCondition();  
        if (!checkOk)  
        {  
            return false;  
        }  
  
        switch (runningNode.status)  
        {  
            case RunStatus.Running:  
                if (!runningNode.Tick(input, output))  
                {  
                    runningNode.Leave(input);  
                    return false;  
                }  
  
                break;  
            default:  
                runningNode.Leave(input);  
                runningNodeIndex++;  
                if(runningNodeIndex >= nodeList_.Count)break;  
                var nextNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
                var check = nextNode.Enter(input);  
                if (!check) return false;  
                break;  
        }  
        return true;  
    }  
  
    public override IBehaviourTreeNode Clone()  
    {  
        var clone = base.Clone() as SequenceNode;  
        clone.canContinue = canContinue;  
        return clone;  
    }  
}

这就是序列节点的设计，但是明显看起来很不爽，里面还出现了一个别扭的变量canContinue 。为什么会出现这个？因为序列节点的特点就是遇到一个子节点FALSE，就会停止并返回FALSE，但是这里我想用序列节点来做根节点，如果是根节点遇到这种情况，那么就不会执行下一个节点，而我看了很多种对于几大节点的描述，似乎都没提到这个。很多都用序列节点做根节点，有些就直接说是根节点。那么要么根节点另外实现，要么改一下序列节点。因为如果序列节点是非根节点的情况下，如果不是每次都从头开始，似乎又会引来新的问题，虽然目前还没想到会出什么问题。不过最后实现执行起来之后发现，用选择节点其实是一样的。所以目前这样的设计，可能是有根本上的问题。希望哪位大神可以指点一下。

然后是选择节点，根据了所有FALSE才返回FALSE的特点设计了

[csharp] view plain copy

public class SelectorNode : BaseCompositeNode, ISelectorNode  
{  
    public bool Enter(object input)  
    {  
        var checkOk = CheckNodeAndCondition();  
        if (!checkOk) return false;  
         
        do  
        {  
            var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
            checkOk = runningNode.Enter(input);  
            if (checkOk) break;  
            runningNodeIndex++;  
            if (runningNodeIndex >= nodeList_.Count) return false;  
        } while (!checkOk);  
          
        status_ = RunStatus.Running;  
        return true;  
    }  
  
    public bool Leave(object input)  
    {  
        var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
        runningNode.Leave(input);  
        runningNodeIndex = 0;  
        status_ = RunStatus.Completed;  
        return true;  
    }  
  
    public bool Tick(object input, object output)  
    {  
        if (status_ == RunStatus.Failure) return false;  
        if (status_ == RunStatus.Completed) return true;  
        var checkOk1 = CheckCondition();  
        if (!checkOk1) return false;  
        var runningNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
        switch (runningNode.status)  
        {  
            case RunStatus.Running:  
                if (!runningNode.Tick(input, output))  
                {  
                    runningNode.Leave(input);  
                    return false;  
                }  
  
                break;  
            default:  
                runningNode.Leave(input);  
                runningNodeIndex++;  
                if (runningNodeIndex >= nodeList_.Count) return false;  
  
                bool checkOk = false;  
                do  
                {  
                    var nextNode = nodeList_[runningNodeIndex] as IBehaviourTreeNode;  
                    checkOk = nextNode.Enter(input);  
                    if (checkOk) break;  
                    runningNodeIndex++;  
                    if (runningNodeIndex >= nodeList_.Count) return false;  
                } while (!checkOk);  
                break;  
        }  
        return true;  
    }  
}

View Code

目前对于我的简单DEMO，组合节点只需要这两个就够了，实际上只需要选择节点、条件节点、动作节点就够了。所以说设计是不完全的，虽然能够实现目标需求，但是实际工作量仍挺大，具体接下来会说明。

行为节点

先放一些渲染节点的代码。实际上我基本上是第一次接触自己去渲染一种数据结构，看完网上的大牛们随随便便就能写出个数据结构的示意图，不得不佩服。我一时半会没想出怎么渲染出树状结构，于是就简单的把树按层分组，一层一层渲染，缺点就是不能很好的表现树的样子，父子关系不能很好的表示。这里放出来希望能抛砖引玉。我以后可能会去完事它，但是现在首先是要搞清楚行为树。实现这个完全是为了看看节点是否正确放置，以方便调试。

[csharp] view plain copy

 
public class RenderableNode  
{  
    public RenderableNode parent;  
    public IBehaviourTreeNode targetNode;  
    public Rect posRect = new Rect();  
    public string name;  
    public int layer;  
    public RunStatus staus;  
    public override string ToString()  
    {  
        return name + "\n" + staus.ToString();  
    }  
    public virtual void Render()  
    {  
        bool running = staus == RunStatus.Running;  
        var rect = posRect;  
        rect.y -= (posRect.height / 2);  
  
        var oldColor = GUI.color;  
         if (running)  
        {  
            GUI.color = Color.green;  
        }  
        GUI.Box(rect, ToString());  
        GUI.color = oldColor;  
  
        if (parent == null && targetNode != null && targetNode.parent!=null)  
        {  
            parent = targetNode.parent.renderNode;  
        }  
        if (parent != null)  
        {  
            Vector2 parentPos = new Vector2();  
            parentPos.x = parent.posRect.x + parent.posRect.width;  
            parentPos.y = parent.posRect.y;  
            GUIHelper.DrawLine(new Vector2(rect.x, rect.y + rect.height / 2), parentPos, running?Color.green:Color.yellow);  
        }  
          
    }  
}  
  
public class RenderableCondictionNode : RenderableNode  
{  
    public IConditionNode targetCondictionNode;  
    public override string ToString() { parent = null; return name; }  
    public override void Render()  
    {  
        var rect = posRect;  
        rect.y -= (posRect.height / 2);  
  
        var oldColor = GUI.color;  
        if (targetCondictionNode.ExternalCondition())  
            GUI.color = Color.green;  
        else  
            GUI.color = Color.blue;  
        GUI.Box(rect, ToString());  
        GUI.color = oldColor;  
    }  
}  
  
public class EmptyNode : RenderableNode { public override void Render() { } }  
  
public class NodeBox  
{  
    public Rect posRect = new Rect();  
    public List<RenderableNode> nodeList = new List<RenderableNode>();  
    public void AddNode(RenderableNode node)  
    {  
        nodeList.Add(node);  
    }  
    public void Render()  
    {  
        posRect.y = Screen.height / 2;  
        Rect rect = new Rect();  
  
        foreach (var node in nodeList)  
        {  
            var n = node;  
            rect.height += (n.posRect.height + 1);  
            rect.width = n.posRect.width + 10;  
        }  
        rect.height += 10;  
        rect.x = posRect.x - rect.width / 2;  
        rect.y = posRect.y - rect.height / 2;  
        //GUI.Box(rect, "");  
        posRect.width = rect.width;  
        posRect.height = rect.height;  
        float height = 0;  
        for (var i = 0; i < nodeList.Count; i++)  
        {  
            var n = nodeList[i];  
            n.posRect.y = rect.y + height + n.posRect.height / 2 + 5;  
            n.posRect.x = rect.x + 5;  
            n.Render();  
            height += n.posRect.height + 1;  
        }  
    }  
}

View Code

放一张渲染出来的效果

bubuko.com,布布扣

虽然每一组都只是简单的居中，不过效果看起来还可以接受

然后从图中就可以看到问题了。所有正条件，都会有一个反条件，不这么做就无法在条件改变时，让当前节点返回FALSE，从而让行为树去寻找其他节点。而如果用状态机来做的话，条件肯定只用判断一次，比如

[csharp] view plain copy

if(run){  
   Run();  
}  
else{  
   Walk();  
}

那么可能就回到最初的组合节点的设计了，组合节点就不得不每次都扫描条件。其实本质上我是在担心开销问题，因为变成节点后，就不在是if else那么简单，而是变成了函数调用的开销。简单的AI还好，如果大量复杂的AI，每次对整棵树进行扫描估计够呛。但是目前的设计，条件节点就会非常多，条件不完备就会出现BUG，似乎也不是非常好的情况。

最后放出一些细节

[csharp] view plain copy

 
class PatrolAction : BaseActionNode {  
  
        public PatrolAction() { nodeName_ += "巡逻行为"; }  
  
        public override bool Tick(object input_, object output_)  
        {  
           // var input = input_ as WarriorInputData;  
            var output = output_ as WarriorOutPutData;  
            output.action = WarriorActon.ePatrol;  
            return true;  
        }  
    }  
  
    class RunAwayAction : BaseActionNode {  
        public RunAwayAction() { nodeName_ += "逃跑行为"; }  
  
        public override bool Tick(object input_, object output_)  
        {  
            // var input = input_ as WarriorInputData;  
            var output = output_ as WarriorOutPutData;  
            output.action = WarriorActon.eRunAway;  
            return true;  
        }  
    }  
  
    class AttackAction : BaseActionNode {  
        public AttackAction() { nodeName_ += "攻击行为"; }  
  
        public override bool Tick(object input_, object output_)  
        {  
            // var input = input_ as WarriorInputData;  
            var output = output_ as WarriorOutPutData;  
            output.action = WarriorActon.eAttack;  
            return true;  
        }  
    }  
  
    class CrazyAttackAction : BaseActionNode {  
        public CrazyAttackAction() { nodeName_ += "疯狂攻击行为"; }  
  
        public override bool Tick(object input_, object output_)  
        {  
            // var input = input_ as WarriorInputData;  
            var output = output_ as WarriorOutPutData;  
            output.action = WarriorActon.eCrazyAttack;  
            return true;  
        }  
    }  
  
    class AlertAction : BaseActionNode  
    {  
        public AlertAction() { nodeName_ += "警戒行为"; }  
        public override bool Tick(object input_, object output_)  
        {  
            // var input = input_ as WarriorInputData;  
            var output = output_ as WarriorOutPutData;  
            output.action = WarriorActon.eAlert;  
            return true;  
        }  
    }  



 

 

[csharp] view plaincopy
 
 
private ICompositeNode rootNode = new SelectorNode();  
    private WarriorInputData inputData = new WarriorInputData();  
    private WarriorOutPutData outputData = new WarriorOutPutData();  
    // Use this for initialization  
    public void Start()  
    {  
        inputData.attribute = GetComponent<CharacterAttribute>();  
  
        rootNode.nodeName += "根";  
  
        //条件  
        var hasNoTarget = new PreconditionNOT(() => { return inputData.attribute.hasTarget; });  
        hasNoTarget.nodeName = "无目标";  
        var hasTarget = new Precondition(hasNoTarget);  
        hasTarget.nodeName = "发现目标";  
        var isAnger = new Precondition(() => { return inputData.attribute.isAnger; });  
        isAnger.nodeName = "愤怒状态";  
        var isNotAnger = new PreconditionNOT(isAnger);  
        isNotAnger.nodeName = "非愤怒状态";  
        var HPLessThan500 = new Precondition(() => { return inputData.attribute.health < 500; });  
        HPLessThan500.nodeName = "血少于500";  
        var HPMoreThan500 = new PreconditionNOT(HPLessThan500);  
        HPMoreThan500.nodeName = "血大于500";  
        var isAlert = new Precondition(() => { return inputData.attribute.isAlert; });  
        isAlert.nodeName = "警戒";  
        var isNotAlert = new PreconditionNOT(isAlert);  
        isNotAlert.nodeName = "非警戒";  
  
  
        var patrolNode = new SequenceNode();  
        patrolNode.nodeName += "巡逻";  
        patrolNode.AddCondition(hasNoTarget);  
        patrolNode.AddCondition(isNotAlert);  
        patrolNode.AddNode(new PatrolAction());  
  
        var alert = new SequenceNode();  
        alert.nodeName += "警戒";  
        alert.AddCondition(hasNoTarget);  
        alert.AddCondition(isAlert);  
        alert.AddNode(new AlertAction());  
          
        var runaway = new SequenceNode();  
        runaway.nodeName += "逃跑";  
        runaway.AddCondition(hasTarget);  
        runaway.AddCondition(HPLessThan500);  
        runaway.AddNode(new RunAwayAction());  
  
        var attack = new SelectorNode();  
        attack.nodeName += "攻击";  
        attack.AddCondition(hasTarget);  
        attack.AddCondition(HPMoreThan500);  
  
        var attackCrazy = new SequenceNode();  
        attackCrazy.nodeName += "疯狂攻击";  
        attackCrazy.AddCondition(isAnger);  
        attackCrazy.AddNode(new CrazyAttackAction());  
        attack.AddNode(attackCrazy);  
  
        var attackNormal = new SequenceNode();  
        attackNormal.nodeName += "普通攻击";  
        attackNormal.AddCondition(isNotAnger);  
        attackNormal.AddNode(new AttackAction());  
        attack.AddNode(attackNormal);  
  
        rootNode.AddNode(patrolNode);  
        rootNode.AddNode(alert);  
        rootNode.AddNode(runaway);  
        rootNode.AddNode(attack);  
        var ret = rootNode.Enter(inputData);  
        if (!ret)  
        {  
            Debug.Log("无可执行节点！");  
        }  
    }  
      
    // Update is called once per frame  
    void Update () {  
        var ret = rootNode.Tick(inputData, outputData);  
  
        if (!ret)  
            rootNode.Leave(inputData);  
  
        if (rootNode.status == RunStatus.Completed)  
        {  
            ret = rootNode.Enter(inputData);  
            if (!ret)  
                rootNode.Leave(inputData);  
        }  
        else if (rootNode.status == RunStatus.Failure)  
        {  
            Debug.Log("BT Failed");  
            enabled = false;  
        }  
  
        if (outputData.action != inputData.action)  
        {  
            OnActionChange(outputData.action, inputData.action);  
            inputData.action = outputData.action;  
        }  
    }  
  
    void OnActionChange(WarriorActon action, WarriorActon lastAction) {  
      //  print("OnActionChange "+action+" last:"+lastAction);  
        switch (lastAction)  
        {  
            case WarriorActon.ePatrol:  
                GetComponent<WarriorPatrol>().enabled = false;  
                break;  
            case WarriorActon.eAttack:  
            case WarriorActon.eCrazyAttack:  
                GetComponent<WarriorAttack>().enabled = false;  
                break;  
            case WarriorActon.eRunAway:  
                GetComponent<WarriorRunAway>().enabled = false;  
                break;  
            case WarriorActon.eAlert:  
                GetComponent<WarriorAlert>().enabled = false;  
                break;  
        }  
  
        switch (action) {   
            case WarriorActon.ePatrol:  
                GetComponent<WarriorPatrol>().enabled = true;  
                break;  
            case WarriorActon.eAttack:  
                var attack = GetComponent<WarriorAttack>();  
                attack.revenge = false;  
                attack.enabled = true;  
                break;  
            case WarriorActon.eCrazyAttack:  
                var crazyAttack = GetComponent<WarriorAttack>();  
                crazyAttack.revenge = true;  
                crazyAttack.enabled = true;  
                break;  
            case WarriorActon.eRunAway:  
                GetComponent<WarriorRunAway>().enabled = true;  
                break;  
            case WarriorActon.eAlert:  
                GetComponent<WarriorAlert>().enabled = true;  
                break;  
            case WarriorActon.eIdle:  
                GetComponent<WarriorPatrol>().enabled = false;  
                GetComponent<WarriorAttack>().enabled = false;  
                GetComponent<WarriorRunAway>().enabled = false;  
                break;  
        }  
    }

View Code

行为树的设计与实现,布布扣,bubuko.com

行为树的设计与实现

原文：http://www.cnblogs.com/123ing/p/3706159.html

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