[LayaAir 2.0]Cannot read property 'rayCast' of undefined

export default class indexscene extends Laya.Script {

 

    constructor(){

        super();  



        this.rotation = new Laya.Vector3(0, 0.01, 0);

        this.point = new Laya.Vector2();

        this.ray = new Laya.Ray(new Laya.Vector3(),new Laya.Vector3());

        //1.开启第四个参数

        let config3D = new Laya.Config3D();

        config3D.isAlpha = true;

        Laya3D.init(0, 0, config3D);

        Laya.stage.scaleMode = Laya.Stage.SCALE_FULL;

        Laya.stage.screenMode = Laya.Stage.SCREEN_NONE;

        //2.设置舞台背景色为空

        Laya.stage.bgColor = null;

        this.scene = new Laya.Scene3D();

        this.camera = new Laya.Camera(0, 0.1, 100);

        Laya.stage.addChild(this.scene);

        this.scene.addChild(this.camera);

        this.camera.transform.translate(new Laya.Vector3(0, 3.5, 1));

        this.camera.transform.rotate(new Laya.Vector3(-15, 0, 0), true, false);

        //3.清除照相机颜色

        this.camera.clearColor = null;

        this.directionLight = new Laya.DirectionLight();

        this.scene.addChild(this.directionLight);

        this.directionLight.direction = new Laya.Vector3(0, -0.8, -1);

        this.directionLight.color = new Laya.Vector3(0.7, 0.6, 0.6);

        Laya.Sprite3D.load("res/scene/LayaScene_webgl_sky/Conventional/webgl_sky.lh", Laya.Handler.create(this, this.onLoadFinish)); 



        Laya.stage.on(Laya.Event.MOUSE_DOWN, this, this.mouseDown);

    }

    onLoadFinish(layaMonkey){

        this.layaMonkey=this.scene.addChild(layaMonkey);  

        // Laya.timer.frameLoop(1, this, this.onFrameLoop);

    }

    onFrameLoop(){

        this.layaMonkey.transform.rotate(this.rotation, false);  

    }

    mouseDown(){

		this.point.x = Laya.MouseManager.instance.mouseX;

		this.point.y = Laya.MouseManager.instance.mouseY;

        //产生射线 

		this.camera.viewportPointToRay(this.point, this.ray);

        var out = new Laya.CannonHitResult(); 

        this.scene.cannonPhysicsSimulation.rayCast(this.ray,out); 

		if(out.succeeded)

		{

            console.log(111);

		}

		

	}

}