actionscript-3 - Alternativa3d 8 中的鼠标拖动？

Question

所以我看到了几个使用鼠标在 Alternativa3d 中拖动对象的好例子：

http://wonderfl.net/c/hrsq/read

http://www.thetechlabs.com/3d/dragging-3d-objects-in-flex-3-using-alternativa3d-and-actionscript-3/

但它们适用于引擎的早期版本，并且它们包含现在已弃用的代码，如果您愿意的话，没有直接的正向翻译。请帮忙！

Answer 1

这是我根据您发布的 Wonderfl 示例使用 alternativa3d 8.27.0 制作的版本。希望能帮助到你..

package {

import alternativa.engine3d.core.events.MouseEvent3D;
import alternativa.engine3d.core.RayIntersectionData;
import flash.display.Sprite;
import flash.events.Event;
import flash.display.Stage3D;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import alternativa.engine3d.primitives.Box;
import alternativa.engine3d.core.Resource;
import alternativa.engine3d.controllers.SimpleObjectController;
import alternativa.engine3d.core.Camera3D;
import alternativa.engine3d.core.Object3D;
import alternativa.engine3d.core.View;
import alternativa.engine3d.materials.FillMaterial;
import flash.events.MouseEvent;
import flash.geom.Vector3D;

/**
 * ...
 * @author David E Jones
 */
public class Main extends Sprite 
{
    private var scene:Object3D = new Object3D();
    private var camera:Camera3D;
    private var controller:SimpleObjectController;
    private var stage3D:Stage3D;
    private var box:Box;
    private var boxSelected:Boolean = false;
    private var startPoint:Vector3D;

    public function Main():void 
    {
        if (stage) init();
        else addEventListener(Event.ADDED_TO_STAGE, init);
    }

    private function init(e:Event = null):void 
    {
        removeEventListener(Event.ADDED_TO_STAGE, init);

        stage.align = StageAlign.TOP_LEFT;
        stage.scaleMode = StageScaleMode.NO_SCALE;

        camera = new Camera3D(1, 1000);
        camera.view = new View(stage.stageWidth, stage.stageHeight, false, 0, 0, 4);
        camera.view.backgroundColor = 0x000000;
        addChild(camera.view);
        addChild(camera.diagram);

        camera.x = -30;
        camera.y = -30;
        camera.z = 0;
        controller = new SimpleObjectController(stage, camera, 200);
        controller.lookAt(new Vector3D(0,0,0));
        scene.addChild(camera);

        stage3D = stage.stage3Ds[0];
        stage3D.addEventListener(Event.CONTEXT3D_CREATE, onContextCreate);
        stage3D.requestContext3D();
    }

    private function onContextCreate(e:Event):void {
        stage3D.removeEventListener(Event.CONTEXT3D_CREATE, onContextCreate);

        box = new Box(10, 10, 10, 1, 1, 1, false, null);
        var material:FillMaterial = new FillMaterial( 0xFF0000 );
        box.setMaterialToAllSurfaces(material);
        scene.addChild(box);
        uploadResources(box.getResources(true));

        box.addEventListener(MouseEvent3D.MOUSE_DOWN, onMouseDown);

        stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
        stage.addEventListener(Event.RESIZE, onResize);
        onResize();
    }

    private function onMouseDown(e:MouseEvent3D):void 
    {
        stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
        stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);

        var object:Object3D = e.target as Object3D;
        var origin:Vector3D = new Vector3D();
        var direction:Vector3D = new Vector3D();
        camera.calculateRay(origin, direction, stage.mouseX, stage.mouseY);
        var data:RayIntersectionData = object.intersectRay(origin, direction);

        if (data != null) {
            startPoint = data.point;
        }
    }

    private function onMouseUp(e:MouseEvent):void
    {
        stage.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);
        stage.removeEventListener(MouseEvent.MOUSE_UP, onMouseUp);
    }

    private function onMouseMove(e:MouseEvent):void
    {
        var origin:Vector3D = new Vector3D;
        var directionA:Vector3D = new Vector3D;
        var directionB:Vector3D = new Vector3D;
        var direction:Vector3D = new Vector3D;

        camera.calculateRay(origin, directionA, camera.view.width/2, camera.view.height/2);
        camera.calculateRay(origin, directionB, mouseX, mouseY);

        var pos : Vector3D = intersectionPoint(origin, directionB, new Vector3D(0, startPoint.y, 0), new Vector3D(0, 1, 0));
        box.x = pos.x-startPoint.x;
        box.y = pos.y-startPoint.y;
        box.z = pos.z-startPoint.z;
    }

    public static function intersectionPoint(lineStart:Vector3D, lineDirection:Vector3D, planePosition:Vector3D, planeNormal:Vector3D):Vector3D {

        var result:Vector3D = new Vector3D();
        var w:Vector3D = lineStart.subtract(planePosition);
        var d:Number = planeNormal.dotProduct(lineDirection);
        var n:Number = -planeNormal.dotProduct(w);

        if (Math.abs(d) < 0.0000001) return result;    

        var sI:Number = n / d;

        result.x = lineStart.x + (lineDirection.x * sI);
        result.y = lineStart.y + (lineDirection.y * sI);
        result.z = lineStart.z + (lineDirection.z * sI);

        return result;    
    }

    private function uploadResources(resources:Vector.<Resource>):void {
        for each (var resource:Resource in resources) {
            resource.upload(stage3D.context3D);
        }
    }

    private function onEnterFrame(e:Event):void {
        if (boxSelected) {

        }
        camera.render(stage3D);
    }

    private function onResize(e:Event = null):void {
        camera.view.width = stage.stageWidth;
        camera.view.height = stage.stageHeight;
    }
}

}