动态创建地图及随机资源位置_003-腾讯游戏学院

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class MapManager : MonoBehaviour
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    //Resources资源名字
    [SerializeField] string mapPlaneName;
    [SerializeField] string treePrefabName;
    //地图长宽
    [SerializeField] Vector2 mapSize;
    //要生成的树木数量
    [SerializeField] int treeCount;
    //树之间的最小距离
    [SerializeField] float treesMinDistance;
    //场景物体最大高度，射线检测时，射线发射点需要高于该高度
    float mapMaxHight = 10;
    //随机位置时，最多随机次数
    int randomMaxCount = 20;
    //地面Tag
    string planeTag = "Plane";
    Transform planeObj;
    Transform allTrees;
    Transform treePrefab;
    //记录加载到场景中的树
    List<Transform> treeList = new List<Transform> ();
    void Start () 
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        LoadPlaneAndTree();
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    void LoadPlaneAndTree()
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        if (planeObj == null)
            LoadPlane();
        if (allTrees == null)
            LoadTree();
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    //加载地形，仅限于简单地形
    //地形较简单时，可采用此方法直接加载，稍大地形，可以采用协程，加载完地形之后，在加载其他资源
    //若地形较为复杂，可将地形切割，依次加载，暂不考虑此情况
    void LoadPlane()
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        if(!string.IsNullOrEmpty(mapPlaneName))
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            GameObject newObj = Resources.Load<GameObject>(mapPlaneName);
            if (newObj != null)
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                planeObj = Instantiate(newObj, transform).transform;
                Debug.Log("<color=green> Map Load Success </color>");
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            else
                Debug.Log("<color=red> Map Resources Fail </color>");
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        else
            Debug.Log("<color=red> MapPlaneName is Empty </color>");
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    //加载场景资源
    void LoadTree()
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        //先要有地形
        if (planeObj == null)
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            Debug.Log("<color=red> Plane is Null </color>");
            return;
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        //设置父节点
        if(allTrees == null)
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            allTrees = new GameObject("allTrees").transform;
            allTrees.parent = transform;
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        //预加载prefab
        if (treePrefab == null)
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            if(!string.IsNullOrEmpty(treePrefabName))
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                GameObject newObj = Resources.Load<GameObject>(treePrefabName);
                if (newObj != null)
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                    treePrefab = newObj.transform;
                    Debug.Log("<color=green> TreePrefab Load Success </color>");
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                else
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                    Debug.Log("<color=red> TreePrefab Resources Fail </color>");
                    return;
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            ｝
            else
                Debug.Log("<color=red> TreePrefabName is Empty </color>");
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        //
        StartCoroutine(LoadAllTree());
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    IEnumerator LoadAllTree()
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        yield return new WaitForEndOfFrame();
        //利用协程依次生成
        while(treeList.Count < treeCount)
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            yield return StartCoroutine(LoadOneTree());
            //可在此设置间隔时间，调整加载间隔时间，调节整体效果
            //yield return new WaitForSeconds(0.5f);
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    ｝
    IEnumerator LoadOneTree()
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        //实例化到场景
        Transform newTree = Instantiate(treePrefab, allTrees);
        //随机位置
        newTree.localPosition = GetRandomPosition();
        //添加到list方便后管理
        treeList.Add(newTree);
        yield return new WaitForEndOfFrame();
    ｝
    Vector3 GetRandomPosition()
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        Vector3 randomPos = Vector3.zero;
        bool isOk = false;
        int count = 0;
        while(!isOk)
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            //随机X,Z
            randomPos.x = Random.Range(0, mapSize.x);
            randomPos.z = Random.Range(0, mapSize.y);
            count++;
            isOk = true;
            //计算随机位置与已有位置的距离
            for (int i = 0; i < treeList.Count; i++)
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                if (Vector3.Distance(randomPos, new Vector3(treeList[i].position.x, 0, treeList[i].position.z)) < treesMinDistance)
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                    isOk = false;
                    break;
                ｝
            ｝
            //若随机次数超过指定次数，随机到的位置都小于指定距离，采用此次位置，避免死循环
            if (!isOk && count > randomMaxCount)
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                isOk = true;
                Debug.Log("<color=blue> While Random Count > RandomMaxCount </color>");
            ｝
            //射线检测，确定生成位置的高度
            if (isOk)
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                //射线发射点高于地形最高点，向下发射射线
                randomPos.y = mapMaxHight + 10;
                Ray ray = new Ray(randomPos, Vector3.down);
                RaycastHit hit;
                if (Physics.Raycast(ray, out hit))
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                    //射线检测点是否是地面，若是地面，获取该点Y值
                    if(hit.transform.CompareTag(planeTag))
                        randomPos.y = hit.point.y;
                    else
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                        isOk = false;
                        Debug.Log("<color=blue> Ray Position is not Plane </color>");
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                else
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                    isOk = false;
                    Debug.Log("<color=blue> Ray is Error </color>");
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            ｝
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        return randomPos;
    ｝
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