Camera.ScreenToViewportPoint

Description

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.

// When attached to a GUITexture object, this will
// move the texture around with the mouse.

function Update () {
    transform.position = Camera.main.ScreenToViewportPoint(Input.mousePosition);
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Update() {
        transform.position = Camera.main.ScreenToViewportPoint(Input.mousePosition);
    }
}