Away3D 4.1.4 中实现骨骼绑定

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。

 

转载于:https://www.cnblogs.com/ch06src/p/3430951.html