public Ray ScreenPointToRay (Vector3 pos);



产生的光线位于世界空间中,从摄像机的近平面开始,并通过屏幕上 位置的 (x,y) 像素坐标(忽略 position.z)。

屏幕空间以像素定义。屏幕的左下角为 (0,0),右上角为 (pixelWidth -1,pixelHeight -1)。

//Attach this script to your Camera
//This draws a line in the scene view going through a point 200 pixels from the lower-left corner of the screen
//To see this, enter Play Mode and switch to the Scene tab. Zoom into your Camera's position.
using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { Camera cam;

void Start() { cam = GetComponent<Camera>(); }

void Update() { Ray ray = cam.ScreenPointToRay(new Vector3(200, 200, 0)); Debug.DrawRay(ray.origin, ray.direction * 10, Color.yellow); } }