diff --git a/CAABoxCollisionTree.bt b/CAABoxCollisionTree.bt
new file mode 100644
index 0000000..c41632e
--- /dev/null
+++ b/CAABoxCollisionTree.bt
@@ -0,0 +1,66 @@
+#ifndef _CAABOXCOLLISIONTREE
+#define _CAABOXCOLLISIONTREE
+
+#include "CTransform4f.bt"
+
+struct CCollisionMaterial {
+  uint orientation;
+  uint materialType;
+  uint worldType;
+  uint behaviorList;
+  uint filterList;
+};
+
+struct CIndexedTriangle {
+  uint idx1;
+  uint idx2;
+  uint idx3;
+  ushort material;
+  ushort unk2;
+};
+
+struct CollisionMaterialVector {
+  uint count;
+  CCollisionMaterial collisionMaterials[count];
+};
+
+struct VertexVector {
+  uint count;
+  CVector3f vertices[count];
+};
+
+struct IndexedTriangleVector {
+  uint count;
+  CIndexedTriangle tris[count];
+};
+
+struct ModConData {
+  char id[16];
+  CTransform4f xf;
+  ushort unk;
+};
+
+struct CAABoxCollisionTree(uint64 size) {
+  local uint64 start<format = hex, hidden = true> = FTell();
+  while (FTell() != start + size) {
+    struct Chunk {
+      ChunkDescriptor desc;
+      union {
+        switch (desc.id) {
+        case "MTRL":
+          CollisionMaterialVector materials;
+          break;
+        case "TRIS":
+          IndexedTriangleVector triangles;
+          break;
+        case "VERT":
+          VertexVector vertices;
+          break;
+        }
+        char raw[desc.size];
+      } data;
+    } chunks;
+  }
+};
+
+#endif // _CAABOXCOLLISIONTREE
diff --git a/CTransform4f.bt b/CTransform4f.bt
new file mode 100644
index 0000000..93246f1
--- /dev/null
+++ b/CTransform4f.bt
@@ -0,0 +1,20 @@
+#ifndef _CTRANSFORM4F
+#define _CTRANSFORM4F
+
+struct CTransform4f {
+    float m00;
+    float m01;
+    float m02;
+    float m03;
+    float m10;
+    float m11;
+    float m12;
+    float m13;
+    float m20;
+    float m21;
+    float m22;
+    float m23;
+};
+
+
+#endif// _CTRANSFORM4F
diff --git a/Run.bt b/Run.bt
index 68a1d3b..b4caa25 100644
--- a/Run.bt
+++ b/Run.bt
@@ -14,6 +14,7 @@
 #include "MessageStudioBinaryText.bt"
 #include "MaterialArchive.bt"
 #include "CVectorField.bt"
+#include "CAABoxCollisionTree.bt"
 //#include "CRuleSet.bt"
 #include "CScaleformFlashLibrary.bt"
 
@@ -35,6 +36,9 @@ typedef struct
                 Assert("Invalid version!");
             }
             break;
+        case "CLSN":
+            CAABoxCollisionTree aaboxCollisionTree(form.size);
+            break;
         case "CHPR":
             FCharInf charInfo;
             break;