unity3dUi跟随场景移动，并且做到屏幕外隐藏

3D

image.png

ui

image.png image.png
image.png

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

public class FlowTarget : MonoBehaviour
{

    public enum mode
    {
        ui = 1,
        d3 = 2,
    }

    public GameObject item;

    public int mindis = 5;
    public int maxdis = 20;

    public mode type = mode.ui;

    public GameObject target;

    public Canvas ui_Canvas;
    public Camera UI_Camera;
    public Camera sceneCamera;// camera.main

    // Update is called once per frame
    void Update()
    {
        if (target)
        {
            if (type == mode.ui)
            {
                var dis = Vector3.Distance(sceneCamera.transform.position, target.transform.position);
                if (dis <= mindis || dis > maxdis)
                {
                    item.gameObject.SetActive(false);
                }
                else
                {
                    item.gameObject.SetActive(true);

                    Vector2 mouseDown = sceneCamera.WorldToScreenPoint(target.transform.position);
                    bool isRect = RectTransformUtility.ScreenPointToLocalPointInRectangle(ui_Canvas.transform as RectTransform, mouseDown, UI_Camera, out var mouseUGUIPos);
                    if (isRect && IsInView(target.transform.position))
                    {
                        transform.GetComponent<RectTransform>().anchoredPosition = mouseUGUIPos;
                    }
                    else
                    {
                        item.gameObject.SetActive(false);
                    }
                }
            }
            else
            {
                var dis = Vector3.Distance(sceneCamera.transform.position, target.transform.position);
                if (dis <= mindis || dis > maxdis)
                {
                    item.gameObject.SetActive(false);
                }
                else
                {
                    // 翻转了，需要处理floatitemroot，x=-1
                    transform.position = target.transform.position;
                    transform.LookAt(sceneCamera.transform, Vector3.up);

                    /*Vector2 mouseDown = sceneCamera.WorldToViewportPoint(target.transform.position);
                    if (IsInView(target.transform.position))
                    {
                        item.gameObject.SetActive(true);
                        transform.position = mouseDown;
                        transform.LookAt(sceneCamera.transform);
                    }
                    else
                    {
                        item.gameObject.SetActive(false);
                    }*/
                }
            }
        }
    }

    public bool IsInView(Vector3 worldPos)
    {
        if (type == mode.ui)
        {
            Transform camTransform = sceneCamera.transform;
            Vector2 viewPos = sceneCamera.WorldToViewportPoint(worldPos);
            Vector3 dir = (worldPos - camTransform.position).normalized;
            float dot = Vector3.Dot(camTransform.forward, dir);// 检测对象是否在相机的正前面

            if (dot > 0 && viewPos.x >= 0 && viewPos.x <= 1 && viewPos.y >= 0 && viewPos.y <= 1)
                return true;
            else
                return false;
        }
        else
        {
            Transform camTransform = sceneCamera.transform;
            Vector2 viewPos = sceneCamera.WorldToViewportPoint(worldPos);
            Vector3 dir = (worldPos - camTransform.position).normalized;
            float dot = Vector3.Dot(camTransform.forward, dir);// 检测对象是否在相机的正前面

            if (dot > 0 && viewPos.x >= 0 && viewPos.x <= 1 && viewPos.y >= 0 && viewPos.y <= 1)
                return true;
            else
                return false;
        }

    }


}

image.png
image.png
image.png