在 Unity 中鼠标拖动时围绕游戏对象旋转相机

Question

我想在拖动鼠标时围绕游戏对象（比如一个立方体）旋转相机，以模拟游戏对象正在旋转的感觉（就像我们在场景编辑器中旋转对象以及在购物网站中一样）。

下面的脚本是我正在使用的脚本。但有时脚本的行为非常奇怪。摄像机沿与预期方向相反的方向旋转。为什么会这样？我需要对代码进行哪些更改才能使其正常工作？请帮忙。

using UnityEngine;
using System.Collections;

public class ExampleBehaviourScript : MonoBehaviour
{
    public Camera cameraObj;
    public GameObject myGameObj;
    public float speed = 2f;

    void Update()
    {
        RotateCamera();
    }

    void RotateCamera()
    {
        if(Input.GetMouseButton(0))
        {
         cameraObj.transform.RotateAround(myGameObj.transform.position, 
                                         Vector3.up,
                                         -Input.GetAxis("Mouse X")*speed);

         cameraObj.transform.RotateAround(myGameObj.transform.position, 
                                         Vector3.right,
                                         -Input.GetAxis("Mouse Y")*speed);
        } 

    }
}

Answer 1

我认为是参考轴引起的。

因为您使用了Vector3.up、Vector3.right，而不是相机的那个，所以它没有按照预期的方向旋转。 所以，你应该像下面这样改变。

void RotateCamera()
{
    if(Input.GetMouseButton(0))
    {
     cameraObj.transform.RotateAround(myGameObj.transform.position, 
                                     cameraObj.transform.up,
                                     -Input.GetAxis("Mouse X")*speed);

     cameraObj.transform.RotateAround(myGameObj.transform.position, 
                                     cameraObj.transform.right,
                                     -Input.GetAxis("Mouse Y")*speed);
    } 

}

Answer 2

我在 Unity 中使用鼠标或触摸旋转相机的解决方案

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
public class CameraRotator : MonoBehaviour
{
    public Transform target;
    public Camera mainCamera;
    [Range(0.1f, 5f)]
    [Tooltip("How sensitive the mouse drag to camera rotation")]
    public float mouseRotateSpeed = 0.8f;
    [Range(0.01f, 100)]
    [Tooltip("How sensitive the touch drag to camera rotation")]
    public float touchRotateSpeed = 17.5f;
    [Tooltip("Smaller positive value means smoother rotation, 1 means no smooth apply")]
    public float slerpValue = 0.25f; 
    public enum RotateMethod { Mouse, Touch };
    [Tooltip("How do you like to rotate the camera")]
    public RotateMethod rotateMethod = RotateMethod.Mouse;


    private Vector2 swipeDirection; //swipe delta vector2
    private Quaternion cameraRot; // store the quaternion after the slerp operation
    private Touch touch;
    private float distanceBetweenCameraAndTarget;

    private float minXRotAngle = -80; //min angle around x axis
    private float maxXRotAngle  = 80; // max angle around x axis

    //Mouse rotation related
    private float rotX; // around x
    private float rotY; // around y
    private void Awake()
    {
        if (mainCamera == null)
        {
            mainCamera = Camera.main;
        }

        
    }
    // Start is called before the first frame update
    void Start()
    {
        distanceBetweenCameraAndTarget = Vector3.Distance(mainCamera.transform.position, target.position);
    }

    // Update is called once per frame
    void Update()
    {
        if (rotateMethod == RotateMethod.Mouse)
        {
            if (Input.GetMouseButton(0))
            {
                rotX += -Input.GetAxis("Mouse Y") * mouseRotateSpeed; // around X
                rotY += Input.GetAxis("Mouse X") * mouseRotateSpeed;
            }

            if (rotX < minXRotAngle)
            {
                rotX = minXRotAngle;
            }
            else if (rotX > maxXRotAngle)
            {
                rotX = maxXRotAngle;
            }
        }
        else if (rotateMethod == RotateMethod.Touch)
        {
            if (Input.touchCount > 0)
            {
                touch = Input.GetTouch(0);
                if (touch.phase == TouchPhase.Began)
                {
                    //Debug.Log("Touch Began");

                }
                else if (touch.phase == TouchPhase.Moved)
                {
                    swipeDirection += touch.deltaPosition * Time.deltaTime * touchRotateSpeed;
                }
                else if (touch.phase == TouchPhase.Ended)
                {
                    //Debug.Log("Touch Ended");
                }
            }

            if (swipeDirection.y < minXRotAngle)
            {
                swipeDirection.y = minXRotAngle;
            }
            else if (swipeDirection.y > maxXRotAngle)
            {
                swipeDirection.y = maxXRotAngle;
            }
        }

    }

    private void LateUpdate()
    {

        Vector3 dir = new Vector3(0, 0, -distanceBetweenCameraAndTarget); //assign value to the distance between the maincamera and the target

        Quaternion newQ; // value equal to the delta change of our mouse or touch position
        if (rotateMethod == RotateMethod.Mouse)
        {
           newQ  = Quaternion.Euler(rotX , rotY, 0); //We are setting the rotation around X, Y, Z axis respectively
        }
        else
        {
            newQ = Quaternion.Euler(swipeDirection.y , -swipeDirection.x, 0);
        }
        cameraRot = Quaternion.Slerp(cameraRot, newQ, slerpValue);  //let cameraRot value gradually reach newQ which corresponds to our touch
        mainCamera.transform.position = target.position + cameraRot * dir;
        mainCamera.transform.LookAt(target.position);

    }

    public void SetCamPos()
    {
        if(mainCamera == null)
        {
            mainCamera = Camera.main;
        }
        mainCamera.transform.position = new Vector3(0, 0, -distanceBetweenCameraAndTarget);
    }

}

Answer 3

要按照鼠标移动的方向移动立方体，请更改代码，例如：

void RotateCamera()
{
    if (Input.GetMouseButton(0))
    {
        cameraObj.transform.RotateAround(myGameObj.transform.position,
                                        Vector3.up,
                                        Input.GetAxis("Mouse X") * speed);

        cameraObj.transform.RotateAround(myGameObj.transform.position,
                                        Vector3.right,
                                        -Input.GetAxis("Mouse Y") * speed);
    }

}