Camera.ScreenToWorldPoint

# [Camera](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera.html).ScreenToWorldPoint

public [Vector3](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector3.html) **ScreenToWorldPoint** ([Vector3](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector3.html) **position**);

public [Vector3](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector3.html) **ScreenToWorldPoint** ([Vector3](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector3.html) **position**, [Camera.MonoOrStereoscopicEye](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera.MonoOrStereoscopicEye.html) **eye**);

## 参数

| position | 屏幕空间位置（通常为 mouse x, y），加上表示深度的 z 位置（例如，摄像机裁剪面）。                                                                                                                                                                                                                                                                                                                                                             |
| ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| eye      | 默认为 [Camera.MonoOrStereoscopicEye.Mono](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera.MonoOrStereoscopicEye.Mono.html)。可设置为 [Camera.MonoOrStereoscopicEye.Left](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera.MonoOrStereoscopicEye.Left.html) 或 [Camera.MonoOrStereoscopicEye.Right](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera.MonoOrStereoscopicEye.Right.html)，以用于立体渲染（例如，用于 VR）。 |

## 返回

**Vector3** 通过转换到摄像机平面距离为 z 的屏幕空间点创建的世界空间点。

## 描述

将点从屏幕空间变换为世界空间。其中，世界空间定义为位于游戏层级视图最顶层的坐标系统。

即使以离屏坐标的形式提供时，仍可计算世界空间坐标，例如，用于实例化靠近屏幕特定角的离屏对象。

屏幕空间以像素定义。屏幕的左下角为 (0,0)，右上角 为 ([pixelWidth](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera-pixelWidth.html),[pixelHeight](https://docs.unity3d.com/cn/2019.4/ScriptReference/Camera-pixelHeight.html))。z 位置为与摄像机的距离，采用世界单位。

```
// Convert the 2D position of the mouse into a
// 3D position.  Display these on the game window.

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    private Camera cam;

void Start()
    {
        cam = Camera.main;
    }

void OnGUI()
    {
        Vector3 point = new Vector3();
        Event   currentEvent = Event.current;
        Vector2 mousePos = new Vector2();

// Get the mouse position from Event.
        // Note that the y position from Event is inverted.
        mousePos.x = currentEvent.mousePosition.x;
        mousePos.y = cam.pixelHeight - currentEvent.mousePosition.y;

point = cam.ScreenToWorldPoint(new Vector3(mousePos.x, mousePos.y, cam.nearClipPlane));

GUILayout.BeginArea(new Rect(20, 20, 250, 120));
        GUILayout.Label("Screen pixels: " + cam.pixelWidth + ":" + cam.pixelHeight);
        GUILayout.Label("Mouse position: " + mousePos);
        GUILayout.Label("World position: " + point.ToString("F3"));
        GUILayout.EndArea();
    }
}
```