实现鼠标控制场景的视野及移动

1.移动场景中的物体

using UnityEngine;
using System.Collections;

public class DragAndDrog : MonoBehaviour {

    private GameObject target;
    private bool isMouseDrag;
    private Vector3 screenPosition;
    private Vector3 offset;
	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
        GameObjectDragAndDrog();
	
	}

    //任意拖拽

    private GameObject ReturnGameObjectDrag(out RaycastHit hit)
    {
        target = null;
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        if (Physics.Raycast(ray.origin, ray.direction * 10, out hit))
        {
            target = hit.collider.gameObject;
        }
        return target;
    }

    //拖拽Updata
    private void GameObjectDragAndDrog()
    {
        if (Input.GetMouseButtonDown (0))
        {
            RaycastHit hitInfo;
            target = ReturnGameObjectDrag(out hitInfo);
            if (target != null)
            {
                isMouseDrag = true;
//将目标对象的世界坐标转化为屏幕坐标
                screenPosition = Camera.main.WorldToScreenPoint(target.transform.position);
//得到鼠标的世界坐标与目标世界坐标的偏移量
                offset = target.transform.position - Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPosition.z));
            }      
        }

        if (Input.GetMouseButtonUp(0))
        {
            isMouseDrag = false;
        }

        if (isMouseDrag)
        {

            Vector3 currentScreenSpace = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPosition.z);
//鼠标的世界坐标加上偏移量，即为目标对象的终点
            Vector3 currentPosition = Camera.main.ScreenToWorldPoint(currentScreenSpace) + offset;
//
            target.transform.localPosition = new Vector3(currentPosition.x, currentPosition.y, currentPosition.z);

        }
    }

}

本脚本可以加载任意一个对象GameObject，场景中所有带Collider的对象，当鼠标点击拖动时候都可以沿x和z轴拖动。之前，都是要拖动那个GameObject就会写一个脚本挂在上面，今天实现了不用每一个要拖动的GameObject都挂载脚本，也不用将移动的GameObject赋给某个变量。

2。鼠标滚轮控制视野

void Update () {
        //鼠标滚轮的效果
        //Camera.main.fieldOfView 摄像机的视野
        //Camera.main.orthographicSize 摄像机的正交投影
        //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;
        }
 
}