Camera.ViewportPointToRay 视窗位置转射线

# [Camera](Camera.html).ViewportPointToRay 视窗位置转射线

function *ViewportPointToRay* (*position* : [Vector3](../Vector3/Vector3.html)) : [Ray](../Ray/Ray.html)

*Description* 描述

Returns a ray going from camera through a viewport point.

返回从相机出发穿过视点的一个射线。

Resulting ray is in world space, starting on the near plane of the camera and
going through position's (x,y) coordinates on the viewport (position.z is
ignored).

产生的射线是在世界空间中，从相机的近裁剪面开始并穿过视口 POSITION(x,y)坐标（position.z 被忽略）

Viewport coordinates are normalized and relative to the camera. The
bottom-left of the camera is (0,0); the top-right is (1,1).

视窗坐标被规范化，并相对于相机。相机的左下为（0,0）；右上是（1,1）。

* [C#](#)
* [JavaScript](#)

```
using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
	void Update() {
		Ray ray = camera.ViewportPointToRay(new Vector3(0.5F, 0.5F, 0));
		RaycastHit hit;
		if (Physics.Raycast(ray, ref hit))
			print("I'm looking at " + hit.transform.name);
		else
			print("I'm looking at nothing!");
	}
}
```

```
// Prints the name of the object camera is directly looking at
//打印相机直接看到物体名称

function Update () {
	// Get the ray going through the center of the screen
	//获取穿过屏幕中心的射线
	var ray : Ray = camera.ViewportPointToRay (Vector3(0.5,0.5,0));
	// Do a raycast
	//投射
	var hit : RaycastHit;
	if (Physics.Raycast (ray, hit))
	print ("I'm looking at " + hit.transform.name);
	else
	print ("I'm looking at nothing!");
}
```