Unity3D 八叉树划分空间和可视化

也许更好的阅读体验

成果展示

所有层
第一层

第二层

代码

OctreeNode

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class OctreeNode
{//空间内包含的物体public List<GameObject> areaObjects;//空间中心public Vector3 center;//空间大小public float size;//子节点个数 private int kidCount = 8;//子节点public OctreeNode[] kids;//构造函数public OctreeNode (Vector3 center, float size){this.center = center;this.size = size;kids = new OctreeNode[kidCount];areaObjects = new List<GameObject>();}#region 八个子节点中心对应的偏移方向public static Vector3[] centerOffset = new Vector3[8] {new Vector3 (-1, 1, -1),new Vector3 (1, 1, -1),new Vector3 (-1, 1, 1),new Vector3 (1, 1, 1),new Vector3 (-1, -1, -1),new Vector3 (1, -1, -1),new Vector3 (-1, -1, 1),new Vector3 (1, -1, 1)};#endregion#region 空间和内部物体管理//空间内物体树public int objectCount => areaObjects.Count;//把该空间画出来public void DrawGizmos (){Gizmos.DrawWireCube(center, Vector3.one * size);}//判断是否包含某个点public bool Contains (Vector3 position){float halfSize = size / 2.0f;return Mathf.Abs(position.x - center.x) <= halfSize &&Mathf.Abs(position.y - center.y) <= halfSize &&Mathf.Abs(position.z - center.z) <= halfSize;}//清理空间内物体public void Clear (){areaObjects.Clear();}//添加物体public void AddGameObject (GameObject obj){areaObjects.Add(obj);}#endregion}

Orctree

using System.Collections;
using System.Collections.Generic;
using System.ComponentModel.Design.Serialization;
using Unity.VisualScripting;
using UnityEngine;//可视化模式
public enum OctreeDebugMode
{AllDepth,TargetDepth
}
public class Octree : MonoBehaviour
{#region 物体生成和构建八叉树//生成物体数[Range(0, 500)]public int genCount = 500;//物体生成范围[Range(1, 300)]public float range = 100;//生成的物体public List<GameObject> sceneObjects;//Octree最大层数[Range(1, 8)]public int maxDepth = 3;//Octree的根节点public OctreeNode root;// Start is called before the first frame updatevoid Start(){GenObjects();OctreePartition();}//随机生成一些cubeprivate void GenObjects(){float genRange = range * 0.5f;sceneObjects = new List<GameObject>();for (int i = 0; i < genCount; ++i){GameObject obj = GameObject.CreatePrimitive(PrimitiveType.Cube);obj.transform.position = new Vector3(Random.Range(-genRange, genRange),Random.Range(-genRange, genRange),Random.Range(-genRange, genRange));obj.hideFlags = HideFlags.HideInHierarchy;sceneObjects.Add(obj);}}//进行八叉树划分private void OctreePartition (){//设定根节点Vector3 origin = Vector3.one;root = new OctreeNode(Vector3.zero, range);root.areaObjects = sceneObjects;//往下生成八叉树 根节点层数为1GenerateOcetree(root, range, 2);}//递归往下生成八叉树private void GenerateOcetree (OctreeNode root, float range, int depth){//depth是当前生成的层数if (depth > maxDepth) return;//下一层的大小float halfRange = range / 2.0f;//根节点偏移量float rootOffset = halfRange / 2.0f;for (int i = 0; i < 8; ++i){Vector3 origin = root.center + OctreeNode.centerOffset[i] * rootOffset;root.kids[i] = new OctreeNode(origin, halfRange);}PartitionSceneObjects(root);for (int i = 0; i < 8; ++i){if (root.kids[i].objectCount >= 2) GenerateOcetree(root.kids[i], halfRange, depth + 1);}}//把空间内物体划分给子节点private void PartitionSceneObjects(OctreeNode root){foreach (GameObject obj in root.areaObjects){foreach (OctreeNode kid in root.kids){if (kid.Contains(obj.transform.position)){kid.AddGameObject(obj);}}}}#endregion#region 可视化//是否显示八叉树public bool showOctree = true;//可视化类型public OctreeDebugMode octreeDebugMode;//可视化层数[Range(0, 8)]public int displayDepth = 3;//不同深度的可视化颜色public Color[] displayColor;private void OnDrawGizmos(){if (root == null) return;if (showOctree && displayDepth <= maxDepth){//显示所有深度的空间范围if (octreeDebugMode == OctreeDebugMode.AllDepth){DrawNode(root, 1);}//显示指定深度的空间范围(第displayDepth层)else if (octreeDebugMode == OctreeDebugMode.TargetDepth){if (displayDepth > 0 && displayColor.Length >= displayDepth) {Color color = displayColor[displayDepth - 1];color.a = 0.5f;Gizmos.color = color;DrawTargetDepth(root, displayDepth);}}}}//绘制所有节点 当前深度为depthprivate void DrawNode(OctreeNode root, int depth){if (root == null || depth > maxDepth) return;Color color = displayColor[depth - 1];color.a = 0.5f;Gizmos.color = color;root.DrawGizmos();foreach (OctreeNode kid in root.kids){DrawNode(kid, depth + 1);}}//绘制指定层private void DrawTargetDepth (OctreeNode root, int targetDepth){--targetDepth;if (root == null || targetDepth < 0) return;Debug.Log(targetDepth);if (targetDepth == 0){root.DrawGizmos();return;}foreach (OctreeNode kid in root.kids){DrawTargetDepth(kid, targetDepth);}}#endregion
}