unity3d 模型旋转、缩放、拖动

using UnityEngine;
using System.Collections;

public class MouseEvent : MonoBehaviour {

public Transform target;

private float xSpeed = 250.0f;
//private float ySpeed = 120.0f;
private float speed=20.0F;
private float x = 0.0f;
private float y = 0.0f;
private Quaternion mRotation;
public float Damping=10F;
private Vector3 offset;
private Vector3 mousePosition;

private float distance = 10.0f;
private float height = 5.0f;
private float rotationDamping;
private float heightDamping;

// Use this for initialization
void Start () {

}

// Update is called once per frame
void Update () {
if (Input.GetMouseButton (0)) {
//
Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition);
RaycastHit hit;
if (Physics.Raycast (ray, out hit)) {

//旋转
x -= Input.GetAxis("Mouse X") * xSpeed * 0.02F;
y =target.position.y; // Input.GetAxis("Mouse Y")* ySpeed * 0.02F;  //transform.position.y; //

//手机触摸情况
//x -= Input.GetTouch (0).deltaPosition.x * xSpeed * 0.02F;
//y = Input.GetTouch (0).deltaPosition.y * ySpeed * 0.02F;
//y = ClampAngle(y,xSpeed,ySpeed);

mRotation = Quaternion.Euler (y, x, 0);
target.rotation = Quaternion.Lerp (target.rotation, mRotation, Time.deltaTime * Damping);

}

}else if (Input.GetAxis ("Mouse ScrollWheel") != 0) {
//Zoom out
if (Input.GetAxis ("Mouse ScrollWheel") < 0) {
if (Camera.main.fieldOfView <= 100)
Camera.main.fieldOfView += 2;
if (Camera.main.orthographicSize <= 20)
Camera.main.orthographicSize += 0.5F;
}
//Zoom in
if (Input.GetAxis ("Mouse ScrollWheel") > 0) {
if (Camera.main.fieldOfView > 2)
Camera.main.fieldOfView -= 2;
if (Camera.main.orthographicSize >= 1)
Camera.main.orthographicSize -= 0.5F;
}

}

if (Input.GetMouseButton (2)) {
/*
Vector3 screenSpace = Camera.main.WorldToScreenPoint(transform.position);

Vector3 offset = transform.position -Camera.main.ScreenToWorldPoint(new Vector3(mousePosition.x, screenSpace.y, screenSpace.z));
//Vector3 offset = transform.position -Camera.main.ScreenToWorldPoint(new Vector3(Input.GetTouch(0).deltaPosition.x, screenSpace.y, screenSpace.z));

Vector3 curScreenSpace = new Vector3(Input.mousePosition.x, screenSpace.y, screenSpace.z);
//Vector3 curScreenSpace = new Vector3(Input.GetTouch(0).deltaPosition.x, screenSpace.y, screenSpace.z);
Vector3 ss=transform.position+offset;
transform.position = ss;
*/
target.position -= Vector3.right * Time.deltaTime*Input.GetAxis ("Mouse X") * speed;
target.position += Vector3.up * Time.deltaTime*Input.GetAxis ("Mouse Y")* speed;

}
}

void OnGUI ()
{
Event Mouse = Event.current;
//鼠标双击事件
if (Mouse.isMouse && Mouse.type == EventType.MouseDown && Mouse.clickCount == 2)
{
//target.position = new Vector3(Input.GetAxis ("Mouse X")+10.0f,target.position.y,target.position.z+10.0f);
// Calculate the current rotation angles
var wantedRotationAngle = target.eulerAngles.y;
var wantedHeight = target.position.y + height;

var currentRotationAngle = transform.eulerAngles.y;
var currentHeight = transform.position.y;

// Damp the rotation around the y-axis
currentRotationAngle = Mathf.LerpAngle(currentRotationAngle, wantedRotationAngle, rotationDamping * Time.deltaTime);

// Damp the height
currentHeight = Mathf.Lerp(currentHeight, wantedHeight, heightDamping * Time.deltaTime);

// Convert the angle into a rotation
var currentRotation = Quaternion.Euler(0, currentRotationAngle, 0);

// Set the position of the camera on the x-z plane to:
// distance meters behind the target
transform.position = target.position;
transform.position -= currentRotation * Vector3.forward * distance;

// Set the height of the camera
transform.position = new Vector3(transform.position.x ,currentHeight , transform.position.z);

// Always look at the target
transform.LookAt(target);

}
}

#region ClampAngle
static float ClampAngle (float angle, float min, float max)
{
if (angle < -360)
angle += 360;
if (angle > 360)
angle -= 360;
return Mathf.Clamp (angle, min, max);
}
#endregion
}