Local project added

Assets/Scripts/VoxelOctree/VoxelTreeBuilder.cs

@@ -0,0 +1,128 @@
+using UnityEngine;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+public class VoxelTreeBuilder
+{
+    private int maxDepth;
+    private float minNodeSize;
+
+    public VoxelTreeBuilder(int maxDepth, float minNodeSize)
+    {
+        this.maxDepth = maxDepth;
+        this.minNodeSize = minNodeSize;
+    }
+
+    public OctreeNode Build(Bounds bounds, Func<Vector3, float, IsSolidNodeAnswere> isSolid)
+    {
+        return BuildNode(bounds, isSolid, 0);
+    }
+
+    private OctreeNode BuildNode(Bounds bounds, Func<Vector3, float, IsSolidNodeAnswere> isSolid, int depth)
+    {
+        OctreeNode node = new OctreeNode(bounds);
+        IsSolidNodeAnswere answere;
+
+        // Stop subdivision if we reached the maximum depth or smallest size
+        if (depth >= maxDepth)
+        {
+            // Check the voxel state at the center
+            answere = isSolid(bounds.center, bounds.size.x);
+            node.isOccupied = answere.isSolid;
+            node.penetrationFactor = answere.penetrationFactor;
+            node.reflexionFactor = answere.reflexionFactor;
+            return node;
+        }
+
+        if( bounds.size.x <= minNodeSize )
+        {
+            bool allSolid = true;
+            bool allEmpty = true;
+
+            foreach (Vector3 corner in GetCorners(bounds))
+            {
+                answere = isSolid(corner, bounds.size.x);
+                bool solid = answere.isSolid;
+                
+                node.penetrationFactor = answere.penetrationFactor;
+                node.reflexionFactor = answere.reflexionFactor;
+
+                allSolid &= solid;
+                allEmpty &= !solid;
+            }
+
+            // Check if the entire cube is homogeneous (either fully solid or empty)
+            if (depth >= maxDepth || allSolid)
+            {
+                // If homogeneous, stop subdivision
+                if (allSolid || allEmpty)
+                {
+                    if (allSolid)
+                    {
+                        answere = isSolid(bounds.center, bounds.size.x);
+                        node.isOccupied = answere.isSolid;
+                        node.penetrationFactor = answere.penetrationFactor;
+                        node.reflexionFactor = answere.reflexionFactor;
+                        node.isOccupied = allSolid;
+                    }
+                    
+                    return node;
+                }
+            }   
+        }
+
+        // Otherwise, subdivide into 8 child nodes
+        node.isLeaf = false;
+        int arrayIndex = 0;
+
+        foreach (var (i, subBounds) in GetSubBounds(bounds).Select((b, i) => (i, b)))
+        {
+            OctreeNode childrenNode = BuildNode(subBounds, isSolid, depth + 1);
+
+            if (childrenNode.isOccupied == true || childrenNode.hasChildrenOccupied == true)
+            {
+                node.hasChildrenOccupied = true;
+                node.children[arrayIndex] = childrenNode;
+            }
+            else
+            {
+                node.children[arrayIndex] = null;
+            }
+            arrayIndex++;
+        }
+
+        if (arrayIndex == 0)
+            node.isLeaf = true;
+
+        return node;
+    }
+
+    private IEnumerable<Bounds> GetSubBounds(Bounds parent)
+    {
+        // Generate 8 sub-bounds for the octree subdivision
+        Vector3 size = parent.size / 2f;
+        Vector3 min = parent.min;
+        for (int x = 0; x < 2; x++)
+            for (int y = 0; y < 2; y++)
+                for (int z = 0; z < 2; z++)
+                {
+                    Vector3 center = min + Vector3.Scale(new Vector3(x + 0.5f, y + 0.5f, z + 0.5f), size);
+                    yield return new Bounds(center, size);
+                }
+    }
+
+    private IEnumerable<Vector3> GetCorners(Bounds b)
+    {
+        // Return all 8 corners of the bounding box
+        Vector3 min = b.min;
+        Vector3 max = b.max;
+        for (int x = 0; x <= 1; x++)
+            for (int y = 0; y <= 1; y++)
+                for (int z = 0; z <= 1; z++)
+                    yield return new Vector3(
+                        x == 0 ? min.x : max.x,
+                        y == 0 ? min.y : max.y,
+                        z == 0 ? min.z : max.z);
+    }
+}