基于TouchAPI的Unity相机手势交互（旋转缩放移动）

官方的Touch相关数据：
Unity手册的Touch

实现代码：

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

public class CameraControl : MonoBehaviour
{
    
       
    //相机移动速度
    public float m_moveSpeed = 0.1f;
    //目标物体
    public GameObject building;
    public Text textPos;

    // 记录手指触屏的位置  
    private Vector2 m_screenpos = new Vector2();
    private Vector3 oldPosition;
    private Quaternion oldRotation;

    public HybridTest hybridTest;
    // Use this for initialization  
    void Start()
    {
    
    
        //记录开始摄像机的Position
        oldPosition = Camera.main.transform.position;
        oldRotation = Camera.main.transform.rotation;
        Debug.Log("old pos is:" + oldPosition);
        
    }

    // Update is called once per frame  
    void Update()
    {
    
    
        //————————input会监听整个屏幕，就算unity的layout只占一小部分——————————
        if (Input.touchCount <= 0)
        {
    
    
            //ResetCameraPosition();
        }
        else
        {
    
    
            textPos.text = "Pos is:" + Input.touches[0].position + "/" + CheckTouchValid(Input.touches[0].position);
        }

        // 1个手指触摸屏幕  
        if (Input.touchCount == 1)
        {
    
    

            if (!CheckTouchValid(Input.touches[0].position))
            {
    
    
                return ;
            }

            if (Input.touches[0].phase == TouchPhase.Began)
            {
    
    
                // 记录手指触屏的位置  
                //m_screenpos = Input.touches[0].position;
                //Debug.Log("touch pos is:" + m_screenpos);                
            }
            // 手指移动  
            else if (Input.touches[0].phase == TouchPhase.Moved )
            {
    
    
                // 移动摄像机  
                //Camera.main.transform.Translate(new Vector3(-Input.touches[0].deltaPosition.x * Time.deltaTime * m_moveSpeed, -Input.touches[0].deltaPosition.y * Time.deltaTime * m_moveSpeed, 0));

                //让相机围绕目标Y轴旋转
                Camera.main.transform.RotateAround(building.transform.position, building.transform.up, Input.touches[0].deltaPosition.x * Time.deltaTime * m_moveSpeed);
                Camera.main.transform.RotateAround(building.transform.position, Camera.main.transform.right, - Input.touches[0].deltaPosition.y * Time.deltaTime * m_moveSpeed);
            }
        }
        else if (Input.touchCount > 1 )
        {
    
       
            if(!CheckTouchValid(Input.touches[0].position) || !CheckTouchValid(Input.touches[1].position))
            {
    
    
                return;
            }

            // 记录两个手指的位置  
            Vector2 finger1 = new Vector2();
            Vector2 finger2 = new Vector2();

            // 记录两个手指的移动  
            Vector2 mov1 = new Vector2();
            Vector2 mov2 = new Vector2();

            for (int i = 0; i < 2; i++)
            {
    
    
                Touch touch = Input.touches[i];

                if (touch.phase == TouchPhase.Ended)
                    break;

                if (touch.phase == TouchPhase.Moved)
                {
    
    
                    float mov = 0;
                    if (i == 0)
                    {
    
    
                        finger1 = touch.position;
                        mov1 = touch.deltaPosition;

                    }
                    else
                    {
    
    
                        finger2 = touch.position;
                        mov2 = touch.deltaPosition;

                        if (finger1.x > finger2.x)
                        {
    
    
                            mov = mov1.x;
                        }
                        else
                        {
    
    
                            mov = mov2.x;
                        }

                        if (finger1.y > finger2.y)
                        {
    
    
                            mov += mov1.y;
                        }
                        else
                        {
    
    
                            mov += mov2.y;
                        }
                        Camera.main.transform.Translate(0, 0, mov * Time.deltaTime * 0.2f);
                    }
                }
            }
            //控制物体始终在屏幕中
            //Camera.main.transform.position = new Vector3(Mathf.Clamp(transform.position.x, -4f, 5.5f), Mathf.Clamp(transform.position.y, 0.5f, 10f), Mathf.Clamp(transform.position.z, -0.9f, 4.6f));

        }
    }

    //通过按钮让物体回到最初的位置
    public void ResetCameraPosition()
    {
    
    
        Camera.main.transform.position = oldPosition;
        Camera.main.transform.rotation = oldRotation;
    }

    public bool CheckTouchValid(Vector2 position)
    {
    
    
        if(position.y < hybridTest.layoutHeight && position.y > 0)
        {
    
    
            return true;
        }

        return false;
    }
}

最下方的函数用于Android开发中识别交互范围，如果不涉及的话可以删掉。
主要原理也就是拿到Touch的position，进行简单的逻辑判断然后进行相机位置的修改。
在Asset store中有个TouchScripts可以免费使用，效果也很不错。

TouchScript的Store地址