papervision3d相機旋轉（papervision3d camera orbit）

原文地址 http://bvu.javaeye.com/blog/393116

有了這個，就可以做三維物體的瀏覽了。

 

 1 package
 2 {
 3     import flash.events.MouseEvent;
 4     
 5     import org.papervision3d.lights.PointLight3D;
 6     import org.papervision3d.materials.shadematerials.FlatShadeMaterial;
 7     import org.papervision3d.objects.DisplayObject3D;
 8     import org.papervision3d.objects.primitives.Sphere;
 9     import org.papervision3d.view.BasicView;
10     
11     [SWF(width="640", height="480", backgroundColor="#000000", frameRate="60")]
12     public class OrbitingCameraExample extends BasicView
13     {
14         private var isOribiting:Boolean;
15         private var cameraPitch:Number = 90;
16         private var cameraYaw:Number = 270;
17         private var cameraTarget:DisplayObject3D = DisplayObject3D.ZERO;
18         private var previousMouseX:Number;
19         private var previousMouseY:Number;
20         
21         private var light:PointLight3D;
22         
23         public function OrbitingCameraExample()
24         {
25             light = new PointLight3D();
26             var material:FlatShadeMaterial = new FlatShadeMaterial(light, 0xcc0000);
27             
28             var sphere1:Sphere = new Sphere(material, 300, 10, 10);
29             var sphere2:Sphere = new Sphere(material, 100, 10, 10);
30             sphere2.x = 300;
31             sphere2.y = 300;
32             sphere2.z = 700
33             var sphere3:Sphere = new Sphere(material, 100, 10, 10);
34             sphere3.x = 600;
35             sphere3.y = -400;
36             sphere3.z = -200;
37             var sphere4:Sphere = new Sphere(material, 100, 10, 10);
38             sphere4.x = -700;
39             sphere3.z = -100;
40             
41             scene.addChild(sphere1);
42             scene.addChild(sphere2);
43             scene.addChild(sphere3);
44             scene.addChild(sphere4);
45             
46             stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
47             stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
48             stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
49 
50             startRendering();
51         }
52 
53         private function onMouseDown(event:MouseEvent):void
54         {
55             isOribiting = true;
56             previousMouseX = event.stageX;
57             previousMouseY = event.stageY;
58         }
59 
60         private function onMouseUp(event:MouseEvent):void
61         {
62             isOribiting = false;
63         }
64         
65         private function onMouseMove(event:MouseEvent):void
66         {
67             var differenceX:Number = event.stageX - previousMouseX;
68             var differenceY:Number = event.stageY - previousMouseY;
69             
70             if(isOribiting)
71             {
72                 cameraPitch += differenceY;
73                 cameraYaw += differenceX;
74                  
75                 cameraPitch %= 360;
76                 cameraYaw %= 360;
77                 
78                 cameraPitch = cameraPitch > 0 ? cameraPitch : 0.0001;
79                 cameraPitch = cameraPitch < 90 ? cameraPitch : 89.9999;
80                 
81                 previousMouseX = event.stageX;
82                 previousMouseY = event.stageY;
83                 
84                 camera.orbit(cameraPitch, cameraYaw, true, cameraTarget);
85             }
86         }
87     }
88 }