简单RTSCamera实现

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

public class TopCameraSelect : MonoBehaviour
{
    public static TopCameraSelect Instance;
    public bool disableSelect = false;
    public Color selectColor = Color.green;
    public float selectLineWidth = 2f;

    public float lookDamper = 5f;
    public string selectionObjectName = "RTS Selection";
    private bool isDrag;
    private Vector3 selectStartPosition;
    private Texture2D pixel;
    private GameObject selection;
    public LinkedList<GameObject> selectObjects = new LinkedList<GameObject>();
    private void Awake()
    {
        Instance = this;
    }
    void Start()
    {
        setPixel(selectColor);
        selection = new GameObject(selectionObjectName);
        {
            var collider = selection.AddComponent<BoxCollider>() as BoxCollider;
            collider.isTrigger = true;
            Vector3 size = new Vector3(1, 100000f, 1);
            collider.size = size;
        }
        var body = selection.AddComponent<Rigidbody>() as Rigidbody;
        body.useGravity = false;

        selection.SetActive(false);
    }
    void Update()
    {
        updateDragging();
    }
    public bool HasSelectObj
    {
        get
        {
            if (selectObjects.Count > 0)
                return true;
            return false;
        }

    }

    public Vector3 GetSelectObjCenter()
    {
        if (HasSelectObj)
        {
            Debug.LogError("错误");
            return Vector3.zero;
        }
        Vector3 vector3 = new Vector3();
        foreach (GameObject go in selectObjects)
            vector3 += go.transform.position;
        vector3 = vector3 / selectObjects.Count;
        return vector3;
    }
    void OnGUI()
    {
        if (!isDrag || disableSelect) return;
        var x = selectStartPosition.x;
        var y = Screen.height - selectStartPosition.y;
        var width = (Input.mousePosition - selectStartPosition).x;
        var height = (Screen.height - Input.mousePosition.y) - y;
        GUI.DrawTexture(new Rect(x, y, width, selectLineWidth), pixel);
        GUI.DrawTexture(new Rect(x, y, selectLineWidth, height), pixel);
        GUI.DrawTexture(new Rect(x, y + height, width, selectLineWidth), pixel);
        GUI.DrawTexture(new Rect(x + width, y, selectLineWidth, height), pixel);
    }
    public void AddSelectObj(GameObject obj)
    {
        if (selectObjects.Contains(obj))
            return;
        selectObjects.AddLast(obj);
    }
    private void setPixel(Color color)
    {
        pixel = new Texture2D(1, 1);
        pixel.SetPixel(0, 0, color);
        pixel.Apply();
    }
    private void updateDragging()
    {
        if (Input.GetMouseButtonDown(0) && !isDrag)
        {
            isDrag = true;

            selectStartPosition = Input.mousePosition;
            if (selection != null)
            {
                selection.SetActive(true);
                if (selectObjects.Count > 0)
                {
                    foreach (GameObject item in selectObjects)
                    {
                        item.GetComponent<Renderer>().material.color = Color.red;
                    }
                    selectObjects.Clear();
                }
            }
        }
        else if (Input.GetMouseButtonUp(0) && isDrag)
        {
            isDrag = false;

            dropSelection(selectStartPosition, Input.mousePosition);
            if (selectObjects.Count > 0)
            {
                foreach (GameObject item in selectObjects)
                {
                    item.GetComponent<Renderer>().material.color = Color.green;
                }
            }
            if (selection != null)
            {
                selection.SetActive(false);
            }
        }
        if (selection.activeSelf)
        {
            dropSelection(selectStartPosition, Input.mousePosition);
        }
    }
    private void dropSelection(Vector3 screenStart, Vector3 screenEnd)
    {
        var start = GetComponent<Camera>().ScreenToWorldPoint(screenStart);
        var finish = GetComponent<Camera>().ScreenToWorldPoint(screenEnd);
        selection.transform.rotation = Quaternion.Euler(transform.localEulerAngles.x - 90, transform.rotation.y, transform.rotation.z);
        selection.transform.position = new Vector3((start.x + finish.x) / 2.0f, (start.y + finish.y) / 2.0f, (start.z + finish.z) / 2.0f);
        selection.transform.localScale = new Vector3(Mathf.Abs(start.x - finish.x), 1f, Mathf.Abs(start.z - finish.z));
    }
}

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class TopCameraController : MonoBehaviour
{
    public Vector2 cameraOffsetXYSpeed = Vector2.one;
    public Vector2 cameraOffset = Vector2.one;
    public LayerMask ground;
    public float height = 5;
    public float mouseWheelSpeed = 0.05f;
    Vector2 viewheightClimp = new Vector2(5, 15);
    Camera my_Camera;
    TopCameraSelect topCameraSelect;
    public static Action<Vector3> PointHit;
    void Awake()
    {
        my_Camera = GetComponent<Camera>();
        topCameraSelect = GetComponent<TopCameraSelect>();
    }
    private void Start()
    {
        my_Camera.transform.position = new Vector3(cameraOffset.x, height, cameraOffset.y);

    }
    private void LateUpdate()
    {
        if (Input.mousePosition.x < 1)
            my_Camera.transform.position += new Vector3(-cameraOffsetXYSpeed.x * Time.deltaTime, 0, 0);
        else if (Input.mousePosition.x > Screen.width - 1)
            my_Camera.transform.position += new Vector3(cameraOffsetXYSpeed.x * Time.deltaTime, 0, 0);
        if (Input.mousePosition.y < 1)
            my_Camera.transform.position += new Vector3(0, 0, -cameraOffsetXYSpeed.y * Time.deltaTime);
        else if (Input.mousePosition.y > Screen.height - 1)
            my_Camera.transform.position += new Vector3(0, 0, cameraOffsetXYSpeed.y * Time.deltaTime);
        if (Input.GetMouseButtonDown(1))
        {
            RaycastHit hit;
            Ray ray = my_Camera.ScreenPointToRay(Input.mousePosition);
            if (Physics.Raycast(ray, out hit, 100, ground))
            {
                PointHit?.Invoke(hit.point);
            }
        }
        // 滚轮实现镜头缩进和拉远
        if (Input.GetAxis("Mouse ScrollWheel") != 0)
        {
            my_Camera.orthographicSize = my_Camera.orthographicSize - Input.GetAxis("Mouse ScrollWheel") * mouseWheelSpeed;
            my_Camera.orthographicSize = Mathf.Clamp(my_Camera.orthographicSize, viewheightClimp.x, viewheightClimp.y);
        }
        if (Input.GetAxis("Horizontal") != 0 || Input.GetAxis("Vertical") != 0)
            transform.position = transform.position + new Vector3(Input.GetAxis("Horizontal") * cameraOffsetXYSpeed.x * 0.1f, 0, Input.GetAxis("Vertical") * cameraOffsetXYSpeed.y * 0.1f);
        if (Input.GetKeyDown(KeyCode.F))
        {
            if (topCameraSelect.HasSelectObj)
            {
                Vector3 center = topCameraSelect.GetSelectObjCenter();
                my_Camera.transform.position = center + new Vector3(cameraOffset.x, height, cameraOffset.y);
                my_Camera.transform.LookAt(center);
            }

        }
    }
}

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