PV3D Pivot

away3d能直接修改物件的中心點
但PV3D並沒有該屬性, 但能透過以下三種方法達到一樣的效果。
1.用DisplayObject3D多包一層。
將物件加入到該DisplayObject3D, 然後對他做旋轉。
http://wonderfl.net/code/7fbfda83de4c282f304b3f11ef59575a1a10d484
2.直接去修改物件的Vertex3D座標。
http://wonderfl.net/code/b7e4f5b3650731820256cf7fbb3461662e2ec0d8
3.使用as3dmod提供的Pivot來更改。
要先下載as3dmod類別喔。

package  {  
import com.as3dmod.modifiers.Pivot;
import com.as3dmod.util.ModConstant; 
import com.as3dmod.ModifierStack; 
import com.as3dmod.plugins.pv3d.LibraryPv3d;  
import org.papervision3d.materials.ColorMaterial; 
import org.papervision3d.materials.utils.MaterialsList;
import org.papervision3d.objects.primitives.Cube;
import org.papervision3d.cameras.CameraType;
import org.papervision3d.view.BasicView; 
import flash.events.Event; 
public class PivotExampleas3dmod extends BasicView {   
private var do3d:Cube;   
public function PivotExampleas3dmod() {
super(800, 600, true, false, CameraType.TARGET);   
init3DObject();
startRendering();   
}
private function init3DObject():void {
var _ml:MaterialsList = new MaterialsList( { all:new ColorMaterial() } );
do3d = new Cube(_ml, 200, 200, 200);
var stack:ModifierStack = new ModifierStack(new LibraryPv3d(), do3d);
var pivot:Pivot = new Pivot( -200, -200, -200);
stack.addModifier(pivot);
stack.collapse();
scene.addChild(do3d);
scene.addChild( new Axes3D());
}  
protected override function onRenderTick(event:Event = null):void {
do3d.rotationY += 2;
super.onRenderTick(event);
}  
}
}

import org.papervision3d.core.geom.*;
import org.papervision3d.core.geom.renderables.*;
import org.papervision3d.materials.special.*;
import org.papervision3d.objects.*;
class Axes3D extends DisplayObject3D {
public function Axes3D() {
var _lines3D:Lines3D = new Lines3D();
var _red :LineMaterial = new LineMaterial(0xff0000);
var _green :LineMaterial = new LineMaterial(0x00ff00);
var _blue :LineMaterial = new LineMaterial(0x0000ff);
var _length :uint = 120;
var _lineX :Line3D = new Line3D(_lines3D, _red, 2, new Vertex3D(-_length, 0, 0), new Vertex3D(_length, 0, 0));
var _lineY :Line3D = new Line3D(_lines3D, _green, 2, new Vertex3D(0, -_length, 0), new Vertex3D(0, _length, 0));
var _lineZ :Line3D = new Line3D(_lines3D, _blue, 2, new Vertex3D(0, 0, -_length), new Vertex3D(0, 0, _length));
_lines3D.addLine(_lineX);
_lines3D.addLine(_lineY);
_lines3D.addLine(_lineZ);
addChild(_lines3D);            
}
}