在Unity移动端中实现缩放

Question

我正在尝试在我的游戏中使用缩放限制来进行缩放。我正在使用以下代码进行滚动和捏合，但我还没有找出如何限制缩放距离（minzoomlimit和maxzoomlimit）。我的意思是，当玩家想要缩小时，他可以缩小一定的距离，当他想要放大时，他可以放大一定的距离。

这是我用于滚动和捏合的代码：

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

public class ScrollAndPinch : MonoBehaviour
{
#if UNITY_IOS || UNITY_ANDROID
    public Camera Camera;
    public bool Rotate;
    protected Plane Plane;
    public float perspectiveZoomSpeed = 0.5f;        // The rate of change of the field of view in perspective mode.
    public float orthoZoomSpeed = 0.5f;





    public Transform Map;

    float distance;

    float MaxDistance = 37063.57f; /*= new Vector3(-3724.8f, 34576.9f, -4562.5f);*/
    float MinDistance = 123302.2f; /*= new Vector3(-18149.0f, 180315.6f, -73023.5f);*/

    private void Awake()
    {
        if (Camera == null)
            Camera = Camera.main;
        Input.multiTouchEnabled = true;

    }

    private void Update()
    {

        //Update Plane
        if (Input.touchCount >= 1)
            Plane.SetNormalAndPosition(transform.up, transform.position);

        var Delta1 = Vector3.zero;
        var Delta2 = Vector3.zero;

        //Scroll
        if (Input.touchCount >= 1)
        {
            Delta1 = PlanePositionDelta(Input.GetTouch(0));
            if (Input.GetTouch(0).phase == TouchPhase.Moved)
                Camera.transform.Translate(Delta1, Space.World);
        }


        //Pinch
        if (Input.touchCount >= 2)
        {
            var pos1 = PlanePosition(Input.GetTouch(0).position);
            var pos2 = PlanePosition(Input.GetTouch(1).position);
            var pos1b = PlanePosition(Input.GetTouch(0).position - Input.GetTouch(0).deltaPosition);
            var pos2b = PlanePosition(Input.GetTouch(1).position - Input.GetTouch(1).deltaPosition);

            //calc zoom
            var zoom = Vector3.Distance(pos1, pos2) /
                       Vector3.Distance(pos1b, pos2b);
            //Debug.Log(zoom);
            //edge case
            if (zoom == 0 || zoom > 10)
                return;

            //Move cam amount the mid ray
            // Camera.fieldOfView = Mathf.Clamp(Camera.fieldOfView, MinDistance, MaxDistance);
            distance = Vector3.Distance(Camera.transform.position, Map.position);
            Camera.transform.position = Vector3.LerpUnclamped(pos1, Camera.transform.position, 1/zoom);




            if (Rotate && pos2b != pos2)

            Camera.transform.RotateAround(pos1, Plane.normal, Vector3.SignedAngle(pos2 - pos1, pos2b - pos1b, Plane.normal));







        }

    }

    protected Vector3 PlanePositionDelta(Touch touch)
    {
        //not moved
        if (touch.phase != TouchPhase.Moved)
            return Vector3.zero;

        //delta
        var rayBefore = Camera.ScreenPointToRay(touch.position - touch.deltaPosition);
        var rayNow = Camera.ScreenPointToRay(touch.position);
        if (Plane.Raycast(rayBefore, out var enterBefore) && Plane.Raycast(rayNow, out var enterNow))
            return rayBefore.GetPoint(enterBefore) - rayNow.GetPoint(enterNow);

        //not on plane
        return Vector3.zero;
    }

    protected Vector3 PlanePosition(Vector2 screenPos)
    {
        //position
        var rayNow = Camera.ScreenPointToRay(screenPos);
        if (Plane.Raycast(rayNow, out var enterNow))
            return rayNow.GetPoint(enterNow);

        return Vector3.zero;
    }

    private void OnDrawGizmos()
    {
        Gizmos.DrawLine(transform.position, transform.position + transform.up);
    }
#endif
}

任何帮助请，谢谢:D。

- Gara

Answer 1

这很简单，你只需要在你的更新函数中添加这段代码即可；

void Update()
{
         if(cam.fieldOfView < minimunDistance)
         {
             cam.fieldOfView = minimunDistance;
         }
         else
         if(cam.fieldOfView > maxDistance)
         {
             cam.fieldOfView = maxDistance;
         }
}

另外，我有一个适用于触摸输入设备和鼠标滚轮的捏和缩放脚本；

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

public class PinchAndZoom : MonoBehaviour
{
    float MouseZoomSpeed = 15.0f;
    float TouchZoomSpeed = 0.1f;
    float ZoomMinBound = 0.1f;
    float ZoomMaxBound = 179.9f;
    Camera cam;

    // Use this for initialization
    void Start()
    {
        cam = GetComponent<Camera>();
    }

    void Update()
    {
        if (Input.touchSupported)
        {
            // Pinch to zoom
            if (Input.touchCount == 2)
            {

                // get current touch positions
                Touch tZero = Input.GetTouch(0);
                Touch tOne = Input.GetTouch(1);
                // get touch position from the previous frame
                Vector2 tZeroPrevious = tZero.position - tZero.deltaPosition;
                Vector2 tOnePrevious = tOne.position - tOne.deltaPosition;

                float oldTouchDistance = Vector2.Distance (tZeroPrevious, tOnePrevious);
                float currentTouchDistance = Vector2.Distance (tZero.position, tOne.position);

                // get offset value
                float deltaDistance = oldTouchDistance - currentTouchDistance;
                Zoom (deltaDistance, TouchZoomSpeed);
            }
        }
        else
        {

            float scroll = Input.GetAxis("Mouse ScrollWheel");
            Zoom(scroll, MouseZoomSpeed);
        }



         if(cam.fieldOfView < ZoomMinBound) 
         {
             cam.fieldOfView = 0.1f;
         }
         else
         if(cam.fieldOfView > ZoomMaxBound ) 
         {
             cam.fieldOfView = 179.9f;
         }
    }

    void Zoom(float deltaMagnitudeDiff, float speed)
    {

        cam.fieldOfView += deltaMagnitudeDiff * speed;
        // set min and max value of Clamp function upon your requirement
        cam.fieldOfView = Mathf.Clamp(cam.fieldOfView, ZoomMinBound, ZoomMaxBound);
    }
}

- user11458208

---

为什么你要两次夹紧它呢？一次在update方法的末尾用if语句，一次在zoom方法中用Mathf.Clamp函数。 - Jayadev Haddadi

很不幸，在Unity编辑器中，如果你使用设备模拟器预览游戏的播放，那么获取滚轮轴的值将始终为0。我想把这个留在这里，以节省像我这样的人的时间。 - seth

Answer 2

在游戏模拟器中可用的变体。只需将鼠标保持在同一位置足够长的时间，它就会开始放大/缩小。

    private float zoomSpeed = 0.1f;
    private float ZoomMinBound = 0.1f;
    private float ZoomMaxBound = 179.9f;
    private Camera cam;

    private bool zooming;
    private float startHoldTime;
    private float holdTime = 0f;
    private const float REQD_HOLD_ZOOM_TIME = 0.5f;
    private bool zoomIn = true;
    private Vector3 lastMousePosition;

    // Use this for initialization
    void Start()
    {
        cam = GetComponent<Camera>();
    }

    void Update()
    {
            if (Input.touchSupported)
            {
                // Pinch to zoom
                if (Input.touchCount == 2)
                {

                    // get current touch positions
                    Touch tZero = Input.GetTouch(0);
                    Touch tOne = Input.GetTouch(1);
                    // get touch position from the previous frame
                    Vector2 tZeroPrevious = tZero.position - tZero.deltaPosition;
                    Vector2 tOnePrevious = tOne.position - tOne.deltaPosition;

                    float oldTouchDistance = Vector2.Distance (tZeroPrevious, tOnePrevious);
                    float currentTouchDistance = Vector2.Distance (tZero.position, tOne.position);

                    // get offset value
                    float deltaDistance = oldTouchDistance - currentTouchDistance;
                    Zoom (deltaDistance, zoomSpeed);
                }
            }
            else
            {
                float scroll = 0;

                if (Input.GetMouseButton(0))
                {
                    if(Input.mousePosition == lastMousePosition)
                    {
                        if(zooming)
                        {
                            holdTime = Time.time - startHoldTime;
                        }
                        else
                        {
                            startHoldTime = Time.time;
                            zooming = true;
                        }

                        if(holdTime > REQD_HOLD_ZOOM_TIME)
                        {
                            if (zoomIn)
                            {
                                scroll = 1;
                            }
                            else 
                            {
                                scroll = -1;
                            }
                        }
                    }
                    else
                    {
                        lastMousePosition = Input.mousePosition;
                        zooming = false;
                    }
                    
                }
                else if(zooming)
                {
                    zoomIn = !zoomIn;
                    scroll = 0;
                    zooming = false;
                }

                if(scroll != 0)
                {
                    Zoom(scroll, zoomSpeed);
                }
            }
    }

正如我在评论中提到的：“不幸的是，在Unity编辑器中，如果你使用设备模拟器预览游戏的播放，那么检索滚轮轴将始终返回0。”

因此，我只使用按钮0事件，因为它在模拟器中有效。

- seth