Away3D基础教程（五）：制作全景功能

效果如下：



制作思路：
1：全景功能其实就是在一个球体内部贴上一张鱼眼全景图片，然后把摄像机放在球体内部中心点，旋转摄像机就可以实现全景效果了。因为全景图要贴到球的内部，所以要把球体的双面贴图功能打开，_SphereGeometry.bothSides = true; 还有一种skyBox贴上6张不同面的全景图制作方法不在此做介绍，全景功能还是用球体方便。

2：使用HoverController这个摄像机控制类， 摄像机围绕球体原点旋转。这个我们经常用来坐360度环绕某点查看某3D物体。或者制作360度全景图。

2:把camera放到球体内部，_view.camera.position = _mesh.position; 设置camera的位置为球体的中心位置，在这里把球体放在了_mesh对象里，所以_mesh的中心位置就是球体的中心位置。

3：鼠标按下并移动开始旋转球体：

_cameraHoverController.panAngle = (mouseX - _mouseX) * .3 + _startX;

_cameraHoverController.tiltAngle = (mouseY - _mouseY) * .3 + _startY;

完整代码如下：

package
{
import away3d.containers.View3D;
import away3d.controllers.HoverController;
import away3d.entities.Mesh;
import away3d.materials.TextureMaterial;
import away3d.primitives.SphereGeometry;
import flash.display.Loader;
import flash.display.MovieClip;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import away3d.utils.Cast;
import away3d.tools.helpers.MeshHelper;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;

/**
* ...
* @author yl
*/
[SWF(width='800',height='600',frameRate="60", backgroundColor="0x000000")]
public class MyAway3d_5 extends Sprite
{
[Embed(source = "../embeds/ball.jpg")]
private static var BallMaterial:Class;private var _startX:Number;
private var _startY:Number;
private var _mouseX:Number;
private var _mouseY:Number;

private var _view:View3D;
private var _cameraHoverController:HoverController;

private var _sphere:SphereGeometry;
private var _sphereMaterial:TextureMaterial;
private var _mesh:Mesh;public function MyAway3d_5()
{
if (stage) {
init();
}else {
this.addEventListener(Event.ADDED_TO_STAGE, init);
}
}private function init(e:Event = null):void {
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
this.removeEventListener(Event.ADDED_TO_STAGE, init);

_view = new View3D();
addChild(_view);
_view.antiAlias = 6;
//摄像机渲染范围2000
_view.camera.lens.far = 2000;

_cameraHoverController = new HoverController(_view.camera, null, 90, 0, 300);
_cameraHoverController.yFactor = 1;
_sphere = new SphereGeometry(1000, 64);
//_sphere.yUp = false;
_sphereMaterial = new TextureMaterial(Cast.bitmapTexture(BallMaterial));
_sphereMaterial.bothSides = true;
_sphereMaterial.smooth = true;
_mesh = new Mesh(_sphere, _sphereMaterial);
//MeshHelper.invertFaces(_mesh);

_view.camera.position = _mesh.position;

_view.scene.addChild(_mesh);this.addEventListener(Event.ENTER_FRAME, onEnterFrame);
stage.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownFunction);
stage.addEventListener(MouseEvent.MOUSE_WHEEL, onWheel);
}private function onWheel(e:MouseEvent):void
{
if (e.delta > 0) {
if (_cameraHoverController.distance > 6) {
_cameraHoverController.distance -= 5;
}
}else if (e.delta < 0) {
if (_cameraHoverController.distance < 600) {
_cameraHoverController.distance += 5;
}
}
}

private function mouseDownFunction(e:MouseEvent):void
{
_startX = _cameraHoverController.panAngle;
_startY = _cameraHoverController.tiltAngle;
_mouseX = mouseX;
_mouseY = mouseY;
stage.addEventListener(MouseEvent.MOUSE_MOVE,mouseMoveFunction);
stage.addEventListener(MouseEvent.MOUSE_UP,mouseUpFunction);
}

private function mouseUpFunction(e:MouseEvent):void
{
stage.removeEventListener(MouseEvent.MOUSE_MOVE,mouseMoveFunction);
stage.removeEventListener(MouseEvent.MOUSE_UP,mouseUpFunction);
//stage.addEventListener(MouseEvent.MOUSE_DOWN,mouseDownFunction);
}

private function mouseMoveFunction(e:MouseEvent):void
{
_cameraHoverController.panAngle = (mouseX - _mouseX) * .3 + _startX;
_cameraHoverController.tiltAngle = (mouseY - _mouseY) * .3 + _startY;
}

private function onEnterFrame(e:Event):void
{
_view.render();
}
}

}