CameraDirectionTracker.cs

using UnityEngine;
using System.Collections;


public class CameraDirectionTracker : MonoBehaviour {

    // Use this for initialization
    void Start () {
    
    }

    void Update () {
        // Get a ray which looks forward from the camera's position:
        Ray ray = new Ray (transform.position, transform.forward);

        // Shoot the ray only at the UIMesh, ignore everything else:
        LayerMask mask = (1 << LayerMask.NameToLayer ("UIMesh"));

        RaycastHit result;
        if (Physics.Raycast (ray, out result, Mathf.Infinity, mask)) {
            // Let the Layout System know at what position we're looking (so it can decide which screen to activate):
            UI.Core.instance.layoutSystem.setLookAtPosition (result.textureCoord);
        }
    }
}