骨骼的绑定归根结底就是将目标骨骼的位置以及旋转数据，同步给要绑定的显示对象。

先来看BindingTag.as

package

away3d.entities

{

    

import

away3d.arcane;

    

import

away3d.animators.SkeletonAnimator;

    

import

away3d.animators.data.JointPose;

    

import

away3d.containers.ObjectContainer3D;

 

    

use

namespace

arcane

    

    

public

class

BindingTag

extends

ObjectContainer3D

    

{

        

private

var

_skeletonAnimator:SkeletonAnimator;

        

private

var

_skeletonIndex:

int

;

 

        

/**

         

*

         

* @param skeletonAnimator

         

* @param skeletonIndex 要绑定的骨骼索引

         

*

         

*/    

        

public

function

BindingTag(skeletonAnimator:SkeletonAnimator, skeletonIndex:

int

)

        

{

            

super

();

            

_skeletonAnimator = skeletonAnimator;

            

_skeletonIndex = skeletonIndex;

        

}

 

        

public

function

notifyBindingTransformChange():

void

        

{

            

invalidateTransform();

        

}

 

        

override

protected

function

updateSceneTransform():

void

        

{

            

if

(_parent)

            

{

                

var

jointPoses:Vector.<JointPose> = _skeletonAnimator.globalPose.jointPoses;

                

if

(jointPoses && jointPoses.length)

                

{

                                        

//取到骨骼数据并同步给当前对象

                    

_sceneTransform.copyFrom( jointPoses[_skeletonIndex].toMatrix3D() );

                    

_sceneTransform.append( _parent.sceneTransform );

                    

_sceneTransform.prepend(transform);

                

}

            

}

            

_sceneTransformDirty =

false

;

        

}

 

        

override

public

function

dispose():

void

        

{

            

//TODO:

        

}

    

}

}

BindingTag即是绑定在指定骨骼上的容器，假如你想绑定武器或特效，只要将他们addChild到该BindingTag就可以了。 下面看怎样将BindingTag集成到Away3D里面。 为AnimatorBase添加Exit_Frame事件，至于为什么要加这个Exit_Frame事件，后面再来解释。分别在start()以及stop()方法里添加、移除Exit_Frame事件

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if (!_broadcaster.hasEventListener(Event.EXIT_FRAME))      _broadcaster.addEventListener(Event.ENTER_FRAME, onExitFrame);   if (_broadcaster.hasEventListener(Event.EXIT_FRAME))      _broadcaster.removeEventListener(Event.EXIT_FRAME, onExitFrame);   protected function onExitFrame(event:Event): void {      //Override }

为SkeletonAnimator添加addBindingTagByName，addBindingTagByIndex方法以及复写onExitFrame

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/**           * 绑定至通过名字指定的骨骼上           * @param boneName           * @return           *           */              public function addBindingTagByName(boneName: String ):BindingTag          {              var boneIndex : int = globalPose.jointPoseIndexFromName(boneName);              if (boneIndex< 0 ) //骨骼不存在                  return null ;              return addBindingTagByIndex(boneIndex);          }            /**           * 绑定至通过骨骼索引指定的骨骼上           * @param boneIndex           * @return           *           */              public function addBindingTagByIndex(boneIndex: int ):BindingTag          {              var bindingTag:BindingTag = new BindingTag( this , boneIndex);                for ( var i: int = 0 ; i < _owners.length; i++)              {                  _owners[i].addChild(bindingTag); //将bindingTag添加至骨骼对应的Mesh              }                if (!_bindingTags)_bindingTags = new Vector.<BindingTag>();              _bindingTags.push(bindingTag);                       return bindingTag;          }            override protected function onExitFrame(event:Event): void          {              if (_bindingTags && _bindingTags.length)              {                  for ( var i: int = 0 ; i < _bindingTags.length; i++)                  {                      _bindingTags[i].notifyBindingTransformChange();                  }              }          }

到这里就已经代码已经都修改添加完成了，下面来说下为什么要在Exit_Frame事件中通知BindingTag更新.骨骼的更新是在skeletonAnimatior的updateGlobalProperties方法中进行的，他的更新是在引擎执行完traverse后执行的，所以为了保证每次执行traverse时都能让BindingTag根据骨骼更新，需在Exit_Frame时通知，否则BindingTag的更新总会延迟一帧，从而导致跟随出现错位问题。