Unity 之鼠标滑动屏幕或拖动物体

直接把代码挂载到相机上面，参数都调好了，想改的自己改，也可以改成拖动物体，直接挂载到需要拖动的物体上面即可，如果拖动位置不对，就把世界坐标系转为屏幕坐标系，我这里用的世界坐标系，最后一行为注释掉的世界坐标系转为屏幕坐标系的方法

using UnityEngine;
using System.Collections;

public class Controll : MonoBehaviour
{

    private bool isMouseDown = false;
    private Vector3 lastMousePosition = Vector3.zero;

    // Update is called once per frame
    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            isMouseDown = true;
        }
        if (Input.GetMouseButtonUp(0))
        {
            isMouseDown = false;
            lastMousePosition = Vector3.zero;
        }
        if (isMouseDown)
        {
           // print("lastMousePosition:    " + lastMousePosition);
           // print("Input.mousePosition:    " + Input.mousePosition);
            if (lastMousePosition != Vector3.zero)
            {
                Vector3 offset = Input.mousePosition - lastMousePosition;  
              //  print("offset:  " + offset);
                transform.position = transform.position -offset*0.05f;

               // print("相机位置:  "+transform.position);

            }
            lastMousePosition = Input.mousePosition;
            //lastMousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);   //世界坐标系转换为屏幕坐标系
        }
    }
}