Away3D Forum Looping SkeletonAnimation shifts mesh up

altunsercan, Newbie
Posted: 12 January 2013 05:59 PM Total Posts: 6

Hi,

I imported an animated model that i exported from Maya using AWD Exporter. I can see the model and the animation however model slightly shifts up at every loop. Here is the code:

package
{
 import away3d.animators.SkeletonAnimationSet;
 import away3d.animators.SkeletonAnimationState;
 import away3d.animators.SkeletonAnimator;
 import away3d.animators.data.Skeleton;
 import away3d.cameras.Camera3D;
 import away3d.cameras.lenses.PerspectiveLens;
 import away3d.containers.Scene3D;
 import away3d.containers.View3D;
 import away3d.entities.Mesh;
 import away3d.events.LoaderEvent;
 import away3d.library.AssetLibrary;
 import away3d.library.AssetLibraryBundle;
 import away3d.loaders.parsers.Parsers;
 
 import flash.display.Sprite;
 import flash.display.StageAlign;
 import flash.display.StageScaleMode;
 import flash.events.Event;
 import flash.geom.Vector3D;
 import flash.net.URLRequest;
 
 public class AnimationTest extends Sprite
 {
  private var bundleLoadCounter:int;
  private var view:View3D;
  public function AnimationTest()
  {
   stage.scaleMode = StageScaleMode.NO_SCALE;
   stage.align = StageAlign.TOP_LEFT;
   
   AssetLibrary.enableParsers( Parsers.ALL_BUNDLED );
   
   var bundle:AssetLibraryBundle = AssetLibrary.getBundle("ninjaOutfit1");
   bundle.addEventListener(LoaderEvent.RESOURCE_COMPLETE, onBundleLoaded );
   bundleLoadCounter = 2;
   bundle.load( new URLRequest( "outfit.awd" ), null);
   bundle.load( new URLRequest( "idle.awd" ), null);
   
  }
  
  public function onBundleLoaded( _e:LoaderEvent ):void
  {
   bundleLoadCounter--;
   if( bundleLoadCounter != 0 )
   {
    return;
   }
   //// Setup Scene
   var camera:Camera3D = new Camera3D(); 
   var scene:Scene3D = new Scene3D();
   view = new View3D();
   view.backgroundColor = 0x7AA8E6;
   view.antiAlias = 16;
   view.scene = scene;
   view.camera = camera;
   
   camera.lens = new PerspectiveLens();
   camera.lens.near = 10;
   camera.lens.far = 500;
   camera.x = 30;
   camera.y = 30;
   camera.z = -60;
   
   camera.lookAt( new Vector3D() );
   this.addChild( view );
   
   this.addEventListener( Event.ENTER_FRAME, onEvent );
   
   // Create object
   var bundle:AssetLibraryBundle = AssetLibrary.getBundle("ninjaOutfit1");
   
   var ninjaMesh:Mesh = Mesh( bundle.getAsset("ninja") );
   var ninjaSkeleton:Skeleton = Skeleton( bundle.getAsset("skeleton") );
   
   var ninjaAnimSet:SkeletonAnimationSet = new SkeletonAnimationSet( 4 );
   
   var idleState:SkeletonAnimationState = SkeletonAnimationState( bundle.getAsset( "idle" ) );
   idleState.looping = true;
   
   ninjaAnimSet.addState("idle", idleState );
   
   var visual:Mesh = Mesh( ninjaMesh.clone() );
   var skelAnimator:SkeletonAnimator = new SkeletonAnimator(  ninjaAnimSet, ninjaSkeleton );
   visual.animator = skelAnimator;
   
   visual.animator.play( "idle" );
   
   
   scene.addChild( visual );
  }
  
  protected function onEvent(event:Event):void
  {
   view.render();
  }  
  
 }
} 

I commented out “applyRootDelta();” in SkeletalAnimator to see if it is the problem. Shifting stopped however no movement on the hips make it look floaty.

Is this a bug?

altunsercan, Newbie
Posted: 12 January 2013 08:23 PM Total Posts: 6 [ # 1 ]

A little update:

I looked around in source code and found these lines in SkeletonClipNode class.

if ((_timeDir > 0 && _nextFrame < _oldFrame) || (_timeDir < 0 && _nextFrame > _oldFrame)) {
 _rootPos.x -= _totalDelta.x*_timeDir;
 _rootPos.y -= _totalDelta.y*_timeDir;
 _rootPos.z -= _totalDelta.z*_timeDir;
} 

Now this appears to be something that is intended to fix shifted rootPosition before animation returned to first frame ( _nextFrame < _oldFrame ). However this seams to be causing my problem, i commented it out and now there is no shifting.

Rob Bateman, Administrator
Posted: 12 January 2013 10:18 PM Total Posts: 120 [ # 2 ]

Hey altunsercan

I can’t be sure but the problem you describe doesn’t sound like a bug, more like a mismatch between the ground-plane positions of your start and end frames of the walk cycle which over time will add up to a significant offset on the y axis. can you check that your root node positions for these frames are at identical y values?

Removing the lines you mention will stop movement on all axis after the loop reaches its end, in theory causing an abrupt jump back to the position of the first frame of animation, which would remove the overal distance the character had travelled up to that point. This doesn’t sound like its happening to you, but its probably not a recommended solution long term

altunsercan, Newbie
Posted: 13 January 2013 09:08 AM Total Posts: 6 [ # 3 ]

Well i guess it is more about how we produce and handle animations. Our team creates animation cycles that looks like hovering people. We handle movement programmaticaly. So not adding up travelled distance is exactly what we want.

May be this should be optional. Jumping back to first frame is the behaviour i want.

altunsercan, Newbie
Posted: 20 January 2013 03:30 PM Total Posts: 6 [ # 4 ]

I am having similar problems when transitioning between animations now. Is there a way to reset animation state to its initial values?

Looping SkeletonAnimation shifts mesh up Software: Away3D 4.x

altunsercan, Newbie Posted: 12 January 2013 05:59 PM Total Posts: 6 Hi, I imported an animated model that i exported from Maya using AWD Exporter. I can see the model and the animation however model slightly shifts up at every loop. Here is the code: package { import away3d.animators.SkeletonAnimationSet; import away3d.animators.SkeletonAnimationState; import away3d.animators.SkeletonAnimator; import away3d.animators.data.Skeleton; import away3d.cameras.Camera3D; import away3d.cameras.lenses.PerspectiveLens; import away3d.containers.Scene3D; import away3d.containers.View3D; import away3d.entities.Mesh; import away3d.events.LoaderEvent; import away3d.library.AssetLibrary; import away3d.library.AssetLibraryBundle; import away3d.loaders.parsers.Parsers; import flash.display.Sprite; import flash.display.StageAlign; import flash.display.StageScaleMode; import flash.events.Event; import flash.geom.Vector3D; import flash.net.URLRequest; public class AnimationTest extends Sprite { private var bundleLoadCounter:int; private var view:View3D; public function AnimationTest() { stage.scaleMode = StageScaleMode.NO_SCALE; stage.align = StageAlign.TOP_LEFT; AssetLibrary.enableParsers( Parsers.ALL_BUNDLED ); var bundle:AssetLibraryBundle = AssetLibrary.getBundle("ninjaOutfit1"); bundle.addEventListener(LoaderEvent.RESOURCE_COMPLETE, onBundleLoaded ); bundleLoadCounter = 2; bundle.load( new URLRequest( "outfit.awd" ), null); bundle.load( new URLRequest( "idle.awd" ), null); } public function onBundleLoaded( _e:LoaderEvent ):void { bundleLoadCounter--; if( bundleLoadCounter != 0 ) { return; } //// Setup Scene var camera:Camera3D = new Camera3D(); var scene:Scene3D = new Scene3D(); view = new View3D(); view.backgroundColor = 0x7AA8E6; view.antiAlias = 16; view.scene = scene; view.camera = camera; camera.lens = new PerspectiveLens(); camera.lens.near = 10; camera.lens.far = 500; camera.x = 30; camera.y = 30; camera.z = -60; camera.lookAt( new Vector3D() ); this.addChild( view ); this.addEventListener( Event.ENTER_FRAME, onEvent ); // Create object var bundle:AssetLibraryBundle = AssetLibrary.getBundle("ninjaOutfit1"); var ninjaMesh:Mesh = Mesh( bundle.getAsset("ninja") ); var ninjaSkeleton:Skeleton = Skeleton( bundle.getAsset("skeleton") ); var ninjaAnimSet:SkeletonAnimationSet = new SkeletonAnimationSet( 4 ); var idleState:SkeletonAnimationState = SkeletonAnimationState( bundle.getAsset( "idle" ) ); idleState.looping = true; ninjaAnimSet.addState("idle", idleState ); var visual:Mesh = Mesh( ninjaMesh.clone() ); var skelAnimator:SkeletonAnimator = new SkeletonAnimator( ninjaAnimSet, ninjaSkeleton ); visual.animator = skelAnimator; visual.animator.play( "idle" ); scene.addChild( visual ); } protected function onEvent(event:Event):void { view.render(); } } } I commented out “applyRootDelta();” in SkeletalAnimator to see if it is the problem. Shifting stopped however no movement on the hips make it look floaty. Is this a bug?
altunsercan, Newbie Posted: 12 January 2013 08:23 PM Total Posts: 6 [ # 1 ] A little update: I looked around in source code and found these lines in SkeletonClipNode class. `if ((_timeDir > 0 && _nextFrame < _oldFrame) \|\| (_timeDir < 0 && _nextFrame > _oldFrame)) { _rootPos.x -= _totalDelta.x_timeDir; _rootPos.y -= _totalDelta.y_timeDir; _rootPos.z -= _totalDelta.z*_timeDir; }` Now this appears to be something that is intended to fix shifted rootPosition before animation returned to first frame ( _nextFrame < _oldFrame ). However this seams to be causing my problem, i commented it out and now there is no shifting.
Rob Bateman, Administrator Posted: 12 January 2013 10:18 PM Total Posts: 120 [ # 2 ] Hey altunsercan I can’t be sure but the problem you describe doesn’t sound like a bug, more like a mismatch between the ground-plane positions of your start and end frames of the walk cycle which over time will add up to a significant offset on the y axis. can you check that your root node positions for these frames are at identical y values? Removing the lines you mention will stop movement on all axis after the loop reaches its end, in theory causing an abrupt jump back to the position of the first frame of animation, which would remove the overal distance the character had travelled up to that point. This doesn’t sound like its happening to you, but its probably not a recommended solution long term
altunsercan, Newbie Posted: 13 January 2013 09:08 AM Total Posts: 6 [ # 3 ] Well i guess it is more about how we produce and handle animations. Our team creates animation cycles that looks like hovering people. We handle movement programmaticaly. So not adding up travelled distance is exactly what we want. May be this should be optional. Jumping back to first frame is the behaviour i want.
altunsercan, Newbie Posted: 20 January 2013 03:30 PM Total Posts: 6 [ # 4 ] I am having similar problems when transitioning between animations now. Is there a way to reset animation state to its initial values?

Looping SkeletonAnimation shifts mesh up

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