选中此项http://unity3d.com/learn/tutorials/projects/survival-shooter/player-character
更新时无效（）{旋转（）}

void Turning ()
{
    // Create a ray from the mouse cursor on screen in the direction of the camera.
    Ray camRay = Camera.main.ScreenPointToRay (Input.mousePosition);

    // Create a RaycastHit variable to store information about what was hit by the ray.
    RaycastHit floorHit;

    // Perform the raycast and if it hits something on the floor layer...
    if(Physics.Raycast (camRay, out floorHit, camRayLength, floorMask))
    {
        // Create a vector from the player to the point on the floor the raycast from the mouse hit.
        Vector3 playerToMouse = floorHit.point - transform.position;

        // Ensure the vector is entirely along the floor plane.
        playerToMouse.y = 0f;

        // Create a quaternion (rotation) based on looking down the vector from the player to the mouse.
        Quaternion newRotation = Quaternion.LookRotation (playerToMouse);

        // Set the player's rotation to this new rotation.
        playerRigidbody.MoveRotation (newRotation);
    }
}

using UnityEngine;
using System.Collections;

public class MouseView : MonoBehaviour 
{
    public float Sensitivity = 0.125f;

    Vector3 _prevMousePosition = Vector3.zero;
    float   _tilt = 0;
    float   _turn = 0;

    void Update () 
    {       
        Vector3 mousePosition = Input.mousePosition;
        if( Input.GetMouseButton( 0 ) )
        {
            _tilt += -( mousePosition.y-_prevMousePosition.y ) * Sensitivity;
            _turn += ( mousePosition.x-_prevMousePosition.x ) * Sensitivity;
        }
        _prevMousePosition = mousePosition;
        transform.localRotation = Quaternion.Euler( _tilt, _turn, 0 );
    }
}