五、Unity摄像机围绕物体旋转两种实现方式

方法一:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CamerMoveTest2 : MonoBehaviour {

    public Transform target;//获取旋转目标
        public float speed = 0.5f;

    private void Update()
    {
        if (Input.GetMouseButton(0))
        {
            camerarotate();
        }
       
        camerazoom();
    }

    private void camerarotate() //摄像机围绕目标旋转操作
    {
        transform.RotateAround(target.position, Vector3.up, speed*Time.deltaTime); //摄像机围绕目标旋转
        var mouse_x = Input.GetAxis("Mouse X");//获取鼠标X轴移动
        var mouse_y = -Input.GetAxis("Mouse Y");//获取鼠标Y轴移动

        if (Input.GetKey(KeyCode.Mouse1))
        {
            transform.Translate(Vector3.left*(mouse_x*15f)*Time.deltaTime);
            transform.Translate(Vector3.up*(mouse_y*15f)*Time.deltaTime);
        }
        if (Input.GetKey(KeyCode.Mouse0))
        {
            transform.RotateAround(target.transform.position, Vector3.up, mouse_x*5);
            transform.RotateAround(target.transform.position, transform.right, mouse_y*5);
        }
    }

    private void camerazoom() //摄像机滚轮缩放
    {
        if (Input.GetAxis("Mouse ScrollWheel") > 0)
            transform.Translate(Vector3.forward*0.5f);
  
        if (Input.GetAxis("Mouse ScrollWheel") < 0)
            transform.Translate(Vector3.forward*-0.5f);
    }
}

方法二:

using System.Collections;  
using System.Collections.Generic;  
using UnityEngine;  
  
public class CameraMove : MonoBehaviour  
{  
    //摄像机距离  
    public float distance = 10.0f;  
    //缩放系数  
    public float scaleFactor = 1f;  
  
  
    public float maxDistance = 30f;  
    public float minDistance = 5f;  
  
  
    //记录上一次手机触摸位置判断用户是在左放大还是缩小手势  
    private Vector2 oldPosition1;  
    private Vector2 oldPosition2;  
  
  
    private Vector2 lastSingleTouchPosition;  
  
    private Vector3 m_CameraOffset;  
    private Camera m_Camera;  
  
    public bool useMouse = true;  
  
    //定义摄像机可以活动的范围  
    public float xMin = -100;  
    public float xMax = 100;  
    public float zMin = -100;  
    public float zMax = 100;  
  
    //这个变量用来记录单指双指的变换  
    private bool m_IsSingleFinger;  
  
    //初始化游戏信息设置  
    void Start()  
    {  
        m_Camera = this.GetComponent<Camera>();  
        m_CameraOffset = m_Camera.transform.position;  
    }  
  
    void Update()  
    {  
        //判断触摸数量为单点触摸  
        if (Input.touchCount == 1)  
        {  
            if (Input.GetTouch(0).phase == TouchPhase.Began || !m_IsSingleFinger)  
            {  
                //在开始触摸或者从两字手指放开回来的时候记录一下触摸的位置  
                lastSingleTouchPosition = Input.GetTouch(0).position;  
            }  
            if (Input.GetTouch(0).phase == TouchPhase.Moved)  
            {  
                MoveCamera(Input.GetTouch(0).position);  
            }  
            m_IsSingleFinger = true;  
  
        }  
        else if (Input.touchCount > 1)  
        {  
            //当从单指触摸进入多指触摸的时候,记录一下触摸的位置  
            //保证计算缩放都是从两指手指触碰开始的  
            if (m_IsSingleFinger)  
            {  
                oldPosition1 = Input.GetTouch(0).position;  
                oldPosition2 = Input.GetTouch(1).position;  
            }  
  
            if (Input.GetTouch(0).phase == TouchPhase.Moved || Input.GetTouch(1).phase == TouchPhase.Moved)  
            {  
                ScaleCamera();  
            }  
  
            m_IsSingleFinger = false;  
        }  
  
  
        //用鼠标的  
        if (useMouse)  
        {  
            distance -= Input.GetAxis("Mouse ScrollWheel") * scaleFactor;  
            distance = Mathf.Clamp(distance, minDistance, maxDistance);  
            if (Input.GetMouseButtonDown(0))  
            {  
                lastSingleTouchPosition = Input.mousePosition;  
                Debug.Log("GetMouseButtonDown:" + lastSingleTouchPosition);  
            }  
            if (Input.GetMouseButton(0))  
            {  
                MoveCamera(Input.mousePosition);  
            }  
        } 
    }  
  
    /// <summary>  
    /// 触摸缩放摄像头  
    /// </summary>  
    private void ScaleCamera()  
    {  
        //计算出当前两点触摸点的位置  
        var tempPosition1 = Input.GetTouch(0).position;  
        var tempPosition2 = Input.GetTouch(1).position;  
  
  
        float currentTouchDistance = Vector3.Distance(tempPosition1, tempPosition2);  
        float lastTouchDistance = Vector3.Distance(oldPosition1, oldPosition2);  
  
        //计算上次和这次双指触摸之间的距离差距  
        //然后去更改摄像机的距离  
        distance -= (currentTouchDistance - lastTouchDistance) * scaleFactor * Time.deltaTime;  
  
  
        //把距离限制住在min和max之间  
        distance = Mathf.Clamp(distance, minDistance, maxDistance);  
  
  
        //备份上一次触摸点的位置，用于对比  
        oldPosition1 = tempPosition1;  
        oldPosition2 = tempPosition2;  
    }  
  
  
    //Update方法一旦调用结束以后进入这里算出重置摄像机的位置  
    private void LateUpdate()  
    {  
        var position = m_CameraOffset + m_Camera.transform.forward * -distance;  
        m_Camera.transform.position = position;  
    }  
  
  
    private void MoveCamera(Vector3 scenePos)  
    {  
        Vector3 lastTouchPostion = m_Camera.ScreenToWorldPoint(new Vector3(lastSingleTouchPosition.x, lastSingleTouchPosition.y, -1));  
        Vector3 currentTouchPosition = m_Camera.ScreenToWorldPoint(new Vector3(scenePos.x, scenePos.y, -1));  
  
        Vector3 v = currentTouchPosition - lastTouchPostion;  
        m_CameraOffset += new Vector3(v.x, 0, v.z) * m_Camera.transform.position.y;  
  
        //把摄像机的位置控制在范围内  
        m_CameraOffset = new Vector3(Mathf.Clamp(m_CameraOffset.x, xMin, xMax), m_CameraOffset.y, Mathf.Clamp(m_CameraOffset.z, zMin, zMax));  
        //Debug.Log(lastTouchPostion + "|" + currentTouchPosition + "|" + v);  
        lastSingleTouchPosition = scenePos;  
    }  
}