【常用】摄像机移动跟随，依据中心点旋转缩放等

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_25601345/article/details/88547610

/// <summary>
/// Mouse orbit.
/// This script use to control a main camera
/// </summary>

using UnityEngine;
using System.Collections;

public class MouseOrbit : MonoBehaviour
{
    //[HideInInspector]
    public GameObject target; //a target look at
    public float xSpeed; //speed pan x
    public float ySpeed; //speed pan y
    public float yMinLimit; //y min limit
    public float yMaxLimit; //y max limit

    public float XMinLimit; //X轴的限制
    public float XMaxLimit;

    public float scrollSpeed; //scroll speed
    public float zoomMin;  //zoom min
    public float zoomMax; //zoom max

    //Private variable
    private float distance;
    private float distanceLerp;
    private Vector3 position;
    private bool isActivated;
    private float x;
    private float y;
    private bool setupCamera;

    // Use this for initialization

    void Start()
    {


        //Warning when not found target
        if (target == null)
        {
            //target = GameObject.FindGameObjectWithTag("Player");

            if (target == null)
            {
                Debug.LogWarning("Don't found player tag please change player tag to Player");
            }
        }


        //Setup Pos
        Vector3 angles = transform.eulerAngles;
        x = angles.y;
        y = angles.x;

        CalDistance();
    }



    void LateUpdate()
    {

        ScrollMouse();
        RotateCamera();
        //if (x < XMinLimit)
        //{
        //    x = XMinLimit;
        //}

        //if (x > XMaxLimit)
        //{
        //    x = XMaxLimit;
        //}
    }

    //Roate camera method
    void RotateCamera()
    {
        if (Input.GetMouseButtonDown(1))
        {

            isActivated = true;

        }

        // if mouse button is let UP then stop rotating camera 
        if (Input.GetMouseButtonUp(1))
        {
            isActivated = false;
        }



        if (target && isActivated)
        {

            y -= Input.GetAxis("Mouse Y") * ySpeed;

            x += Input.GetAxis("Mouse X") * xSpeed;


            y = ClampAngle(y, yMinLimit, yMaxLimit);
            //x = ClampAngle(x, XMinLimit, XMaxLimit);


            Quaternion rotation = Quaternion.Euler(y, x, 0);

            Vector3 calPos = new Vector3(0, 0, -distanceLerp);

            position = rotation * calPos + target.transform.position;

            transform.rotation = rotation;

            transform.position = position;


        }
        else
        {
            Quaternion rotation = Quaternion.Euler(y, x, 0);

            Vector3 calPos = new Vector3(0, 0, -distanceLerp);

            position = rotation * calPos + target.transform.position;

            transform.rotation = rotation;

            transform.position = position;
        }
    }

    //Calculate Distance Method
    void CalDistance()
    {
        distance = zoomMax;
        distanceLerp = distance;
        Quaternion rotation = Quaternion.Euler(y, x, 0);
        Vector3 calPos = new Vector3(0, 0, -distanceLerp);
        position = rotation * calPos + target.transform.position;
        transform.rotation = rotation;
        transform.position = position;
    }

    //Scroll Mouse Method
    void ScrollMouse()
    {
        distanceLerp = Mathf.Lerp(distanceLerp, distance, Time.deltaTime * 5);
        if (Input.GetAxis("Mouse ScrollWheel") != 0 /*&& !GUI_Menu.instance.CheckHoverItemShop() && !GUI_Menu.instance.CheckHoverSkillWindow()*/)
        {
            // get the distance between camera and target

            distance = Vector3.Distance(transform.position, target.transform.position);

            distance = ScrollLimit(distance - Input.GetAxis("Mouse ScrollWheel") * scrollSpeed, zoomMin, zoomMax);

        }
    }

    //Scroll Limit Method
    float ScrollLimit(float dist, float min, float max)
    {
        if (dist < min)

            dist = min;

        if (dist > max)

            dist = max;

        return dist;
    }


    //Clamp Angle Method
    //float ClampAngle(float angle,float min,float max)
    //{
    //	if(angle < -360)
    //		angle += 360;
    //	if(angle > 360)
    //		angle -= 360;
    //	return Mathf.Clamp(angle,min,max);
    //}

    float ClampAngle(float angle, float min, float max)
    {
        if (angle < -360)
            angle += 360;
        if (angle > 360)
            angle -= 360;
        return Mathf.Clamp(angle, min, max);
    }

}