怎么样做门户网站,泰安做百度推广的公司,哪里查网站备案信息,程序员都需要学什么查阅了一些行为树资料#xff0c;目前最主要是参考了这篇文章#xff0c;看完后感觉行为树实乃强大#xff0c;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#xff0c;真正着手起来却发现很多细节无从下手。 总结起来#xff0c;就是#xff1a; 1、行为树… 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 plaincopy 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 { } 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 plaincopy 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; } } 然后实现具体的节点先是序列节点[csharp] view plaincopy 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 plaincopy 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; } } 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 plaincopy 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 ListRenderableNode nodeList new ListRenderableNode(); 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; } } } 放一张渲染出来的效果 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 plaincopy 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 plaincopy 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 GetComponentCharacterAttribute(); 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: GetComponentWarriorPatrol().enabled false; break; case WarriorActon.eAttack: case WarriorActon.eCrazyAttack: GetComponentWarriorAttack().enabled false; break; case WarriorActon.eRunAway: GetComponentWarriorRunAway().enabled false; break; case WarriorActon.eAlert: GetComponentWarriorAlert().enabled false; break; } switch (action) { case WarriorActon.ePatrol: GetComponentWarriorPatrol().enabled true; break; case WarriorActon.eAttack: var attack GetComponentWarriorAttack(); attack.revenge false; attack.enabled true; break; case WarriorActon.eCrazyAttack: var crazyAttack GetComponentWarriorAttack(); crazyAttack.revenge true; crazyAttack.enabled true; break; case WarriorActon.eRunAway: GetComponentWarriorRunAway().enabled true; break; case WarriorActon.eAlert: GetComponentWarriorAlert().enabled true; break; case WarriorActon.eIdle: GetComponentWarriorPatrol().enabled false; GetComponentWarriorAttack().enabled false; GetComponentWarriorRunAway().enabled false; break; } }
