diff --git a/src/AcDream.Core/Physics/PhysicsDataCache.cs b/src/AcDream.Core/Physics/PhysicsDataCache.cs
index 6fd45a4..291aabf 100644
--- a/src/AcDream.Core/Physics/PhysicsDataCache.cs
+++ b/src/AcDream.Core/Physics/PhysicsDataCache.cs
@@ -174,8 +174,48 @@ public sealed class PhysicsDataCache
             var root = cellStruct.PhysicsBSP?.Root;
             int bspRootPolyCount   = root?.Polygons?.Count ?? 0;
             bool bspRootHasChildren = root?.PosNode is not null || root?.NegNode is not null;
+
+            // Recursive walk: count total leaf poly references + how many of
+            // those poly IDs are absent from the resolved dict. If
+            // bspTotalLeafPolys == 0 the BSP has no collidable polys at all.
+            // If bspUnmatchedIds > 0 the BSP references IDs we didn't resolve
+            // (data-deserialization quirk hypothesis).
+            int bspTotalLeafPolys = 0;
+            int bspUnmatchedIds   = 0;
+            if (root is not null)
+            {
+                var stack = new System.Collections.Generic.Stack<DatReaderWriter.Types.PhysicsBSPNode>();
+                stack.Push(root);
+                while (stack.Count > 0)
+                {
+                    var n = stack.Pop();
+                    if (n.Polygons is not null)
+                    {
+                        foreach (var pid in n.Polygons)
+                        {
+                            bspTotalLeafPolys++;
+                            if (!resolved.ContainsKey(pid)) bspUnmatchedIds++;
+                        }
+                    }
+                    if (n.PosNode is not null) stack.Push(n.PosNode);
+                    if (n.NegNode is not null) stack.Push(n.NegNode);
+                }
+            }
+
+            var bs = root?.BoundingSphere;
+            string bsStr = bs is null
+                ? "bsphere=n/a"
+                : System.FormattableString.Invariant(
+                    $"bsphere=({bs.Origin.X:F2},{bs.Origin.Y:F2},{bs.Origin.Z:F2}) r={bs.Radius:F2}");
+
+            // World origin = cellTransform * (0,0,0,1). Tells us where this cell
+            // sits in world coordinates, so we can cross-check whether the
+            // player's worldPos actually lies inside the AABB when transformed
+            // back to local.
+            var worldOrigin = Vector3.Transform(Vector3.Zero, worldTransform);
+
             Console.WriteLine(System.FormattableString.Invariant(
-                $"[cell-cache] envCellId=0x{envCellId:X8} physicsPolyCount={cellStruct.PhysicsPolygons?.Count ?? 0} resolvedCount={resolved.Count} bspRootPolyCount={bspRootPolyCount} bspRootHasChildren={bspRootHasChildren}"));
+                $"[cell-cache] envCellId=0x{envCellId:X8} physicsPolyCount={cellStruct.PhysicsPolygons?.Count ?? 0} resolvedCount={resolved.Count} bspTotalLeafPolys={bspTotalLeafPolys} bspUnmatchedIds={bspUnmatchedIds} {bsStr} aabbMin=({aabbMin.X:F2},{aabbMin.Y:F2},{aabbMin.Z:F2}) aabbMax=({aabbMax.X:F2},{aabbMax.Y:F2},{aabbMax.Z:F2}) worldOrigin=({worldOrigin.X:F2},{worldOrigin.Y:F2},{worldOrigin.Z:F2})"));
         }
     }