某人

/*charCodeAt() 方法可返回指定位置的字符的 Unicode 编码。这个返回值是 0 - 65535 之间的整数。*/
function getByte(str) {
    var len = str.length,
        bytes = 0;
    for (var i = 0; i < str.length; i++) {
        if (str[i].charCodeAt() > 255) {
            bytes++;
        }
    }
    return len + bytes;
}

using UnityEngine;
using System.Collections;

public class MouseMoveCube : MonoBehaviour {

    private void Start()
    {
        StartCoroutine(OnMouseDown());
    }

    private void Update()
    {
        ZoomCube();
    }

    private void ZoomCube()
    {
        //projection:投射方式

        //zoom out
        if (Input.GetAxis("Mouse ScrollWheel") < 0)
        {
            //Perspective：透视
            if (Camera.main.fieldOfView <= 80)
            {
                Camera.main.fieldOfView += 2;
            }

            //Orthographic：正交
            if (Camera.main.orthographicSize <= 18)
            {
                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;
            }
        }
    }

    IEnumerator OnMouseDown()
    {

        //将物体由世界坐标系转换为屏幕坐标系
        Vector3 screenPostion = Camera.main.WorldToScreenPoint(transform.position);

        //将鼠标屏幕坐标转为三维坐标，再算出物体位置与鼠标之间的距离(offset)
        Vector3 offset = transform.position-Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y,
                             screenPostion.z));

        while( Input.GetMouseButton(0) )
        {
            //当前鼠标位置
            Vector3 curMousePostion = new Vector3(Input.mousePosition.x, Input.mousePosition.y,
                screenPostion.z);

            //将鼠标位置转换为世界位置，加上偏移量
            Vector3 curPosition = Camera.main.ScreenToWorldPoint(curMousePostion) + offset;

            //将当前位置赋给世界物体的位置
            transform.position = curPosition;

            yield return new WaitForFixedUpdate();//循环
        }
    }
}