Generate the connectivity graph

Mini Project/Assets/HandleCollision.cs → Mini Project/Assets/CollisionHandler.cs

@@ -2,8 +2,15 @@
 using System.Collections.Generic;
 using UnityEngine;
 
-public class HandleCollision : MonoBehaviour
+public class GraphEdge
 {
+    public MeshTreeNode A, B;
+}
+
+public class CollisionHandler : MonoBehaviour
+{
+    public float EdgeStrength;
+
     // Start is called before the first frame update
     void Start()
     {

Mini Project/Assets/Splitter.cs

@@ -91,6 +91,7 @@ public class Splitter : MonoBehaviour
 {
     private MeshBuilder mesh;
     private MeshTreeNode root;
+    private List<GraphEdge> graph;
 
     float time = 0;
     MeshTreeNode current;
@@ -105,6 +106,7 @@ public class Splitter : MonoBehaviour
         Random.InitState(this.seed);
 
         this.BuildMeshTree();
+        this.BuildConnectivityGraph();
 
         this.GetComponent<MeshFilter>().mesh = this.mesh.GetMesh();
         this.GetComponent<MeshFilter>().mesh.triangles = this.root.triangles;
@@ -122,6 +124,39 @@ public class Splitter : MonoBehaviour
         this.SplitNode(this.root);
     }
 
+    // Compare fragment bounding boxes to create a connectivity graph
+    void BuildConnectivityGraph() {
+        this.graph = new List<GraphEdge>();
+
+        // Collect all fragments in a list
+        List<MeshTreeNode> leaves = new List<MeshTreeNode>();
+        GetLeaves(this.root, ref leaves);
+
+        // Iterate over all leaves/fragments, building a connectivity graph
+        for (int i = 0; i < leaves.Count; i++) {
+            Mesh A = new Mesh { triangles = leaves[i].triangles };
+
+            for (int j = i + 1; j < leaves.Count; j++) {
+                Mesh B = new Mesh { triangles = leaves[j].triangles };
+
+                // Check if the two AABBs intersect
+                if (A.bounds.Intersects(B.bounds))
+                    this.graph.Add(new GraphEdge { A = leaves[i], B = leaves[j] });
+            }
+        }
+
+    }
+
+    // Gather all leaves from a given MeshTree recursively
+    void GetLeaves(MeshTreeNode node, ref List<MeshTreeNode> leaves) {
+        if (node.left != null)
+            GetLeaves(node.left, ref leaves);
+        if (node.right != null)
+            GetLeaves(node.right, ref leaves);
+        if (node.left == null && node.right == null)
+            leaves.Add(node);
+    }
+
     private void Update()
     {
         time += Time.deltaTime;