Layabox 3D遊戲開發學習筆記—射線檢測，滑鼠控制物體運動

核心要點：3D物體碰撞是靠射線檢測，射線與碰撞器相撞獲取對應的碰撞點資訊。

class RayPicking03 {
    private ray: Laya.Ray;
    private point: Laya.Vector2 = new Laya.Vector2();
    private _outHitInfo: Laya.RaycastHit;
    private _position: Laya.Vector3;
    private _upVector3: Laya.Vector3;
    private _vector3: Laya.Vector3;
    private _offsetVector3: Laya.Vector3;
    private box: Laya.MeshSprite3D;
    private _rotateV3:Laya.Vector3;
    private camera: Laya.Camera;
    private label: Laya.Label;
    constructor() {
        Laya3D.init(0, 0, true);//初始化3D
        Laya.stage.scaleMode = "full";//螢幕縮放方式
        Laya.stage.screenMode = "none";
        Laya.Stat.show();

        var scene: Laya.Scene = Laya.stage.addChild(new Laya.Scene()) as Laya.Scene;//新增場景

        this.point = new Laya.Vector2();//位置資訊
        this.ray = new Laya.Ray(new Laya.Vector3(0, 0, 0), new Laya.Vector3(0, 0, 0));//初始化射線
        this._outHitInfo = new Laya.RaycastHit();//初始化射線資訊
        this._position = new Laya.Vector3(0, 0.25, 0);//位置
        this._upVector3 = new Laya.Vector3(0, 1, 0);
        this._rotateV3 = new Laya.Vector3(1, 0, 1);
        this._vector3 = new Laya.Vector3();
        this._offsetVector3 = new Laya.Vector3(0, 0.15, 0)

        //初始化照相機
        this.camera = scene.addChild(new Laya.Camera(0, 0.1, 100)) as Laya.Camera;
        this.camera.transform.translate(new Laya.Vector3(0, 2, 5));
        this.camera.transform.rotate(new Laya.Vector3(-15, 0, 0), true, false);
        this.camera.clearColor = null;

        //方向光
        var directionLight: Laya.DirectionLight = scene.addChild(new Laya.DirectionLight()) as Laya.DirectionLight;
        directionLight.color = new Laya.Vector3(0.6, 0.6, 0.6);
        directionLight.direction = new Laya.Vector3(1, -1, -1);

        var plane: Laya.MeshSprite3D = scene.addChild(new Laya.MeshSprite3D(new Laya.PlaneMesh(6, 6, 10, 10))) as Laya.MeshSprite3D;//建立平面物體
        var planeMat: Laya.StandardMaterial = new Laya.StandardMaterial();//標準材質
        planeMat.diffuseTexture = Laya.Texture2D.load("../bin/res/layabox.png");//新增材質
        planeMat.albedo = new Laya.Vector4(0.9, 0.9, 0.9, 1);
        plane.meshRender.material = planeMat;

        var meshCollider = plane.addComponent(Laya.MeshCollider) as Laya.MeshCollider;//網格碰撞器
        meshCollider.mesh = plane.meshFilter.sharedMesh;//網格過濾器，獲取共享網格

        this.box = scene.addChild(new Laya.MeshSprite3D(new Laya.SphereMesh(0.2, 8, 8))) as Laya.MeshSprite3D;//建立立方體
        var mat: Laya.StandardMaterial = new Laya.StandardMaterial();
        mat.diffuseTexture = Laya.Texture2D.load("../bin/res/layabox.png");
        this.box.meshRender.material = mat;

        Laya.timer.frameLoop(1, this, this.checkHit);

        this.loadUI();
    }
    private checkHit(): void {
        this.box.transform.position = this._position;
        //this.box.transform.rotate(this._rotateV3, true, false)
        //從螢幕空間生成射線
        this.point.elements[0] = Laya.MouseManager.instance.mouseX;//滑鼠X座標
        this.point.elements[1] = Laya.MouseManager.instance.mouseY;//滑鼠Y座標
        this.camera.viewportPointToRay(this.point, this.ray);//從攝像機到滑鼠點選位置生成射線
        Laya.Physics.rayCast(this.ray, this._outHitInfo, 30, 0);//生成射線
    }

    private loadUI(): void {

        this.label = new Laya.Label();
        this.label.text = "點選移動";
        this.label.pos(Laya.Browser.clientWidth / 2.5, 100);
        this.label.fontSize = 50;
        this.label.color = "#40FF40";
        Laya.stage.addChild(this.label);

        //滑鼠事件
        Laya.stage.on(Laya.Event.MOUSE_UP, this, function (): void {
            if (this._outHitInfo.distance !== -1) {
                Laya.Vector3.add(this._outHitInfo.position, this._offsetVector3, this._vector3);
                Laya.Tween.to(this._position, { x: this._vector3.x, y: this._vector3.y, z: this._vector3.z }, 500/**,Ease.circIn*/);
            }
        });
    }
}