我的相机参数：
调用代码：
let ray = camera.screenPointToRay(0,0);
console.log(‘ray’,ray.o,ray.d);
ray = camera.screenPointToRay(640,360);
console.log(‘ray’,ray.o,ray.d);
ray.d的值永远是
{x: -0.5158607041753288, y: -0.29017164609862245, z: -0.8060323502739513}
根本不能正常检测啊
