[LayaAir 2.0]如何让3D物体在xy平面上做曲线运动时其z轴旋转角度也跟着变化？

            //计算与上一次X坐标的差值

            let speedX = newPos.x - pathItem.item.transform.position.x;

            //计算与上一次Y坐标的差值

            let speedY = newPos.y - pathItem.item.transform.position.y;

            let angle = 0;

            //得到差值向量的弧度

            angle = Math.atan2(speedY , speedX);

            //计算与上一次弧度的差值

            let dis = angle - pathItem.angle

            pathItem.angle = angle;

            //物体旋转

            pathItem.item.transform.rotate(new Laya.Vector3(0,0,dis), false, true);

            //物体平移

            pathItem.item.transform.position = new Laya.Vector3(newPos.x, newPos.y, pathItem.item.transform.position.z);