Transforms position
from screen space into viewport space.
Screenspace is defined in pixels. The bottom-left of the screen is (0,0); the right-top
is (pixelWidth,pixelHeight). The z position is in world units from the camera.
Viewport space is normalized and relative to the camera. The bottom-left of the camera is
(0,0); the top-right is (1,1). The z position is in world units from the camera.
using UnityEngine;
public class Example : MonoBehaviour { // When attached to a GUITexture object, this will // move the texture around with the mouse.
void Update() { transform.position = Camera.main.ScreenToViewportPoint(Input.mousePosition); } }