diff --git a/Assets/AstarPathfindingProject/Generators/NavMeshGenerator.cs b/Assets/AstarPathfindingProject/Generators/NavMeshGenerator.cs
index ec278c5..ffe47ee 100644
--- a/Assets/AstarPathfindingProject/Generators/NavMeshGenerator.cs
+++ b/Assets/AstarPathfindingProject/Generators/NavMeshGenerator.cs
@@ -582,13 +582,12 @@ and have a low memory footprint because of their smaller size to describe the sa
        }

        public static void UpdateArea (GraphUpdateObject o, INavmesh graph) {
-
-           //System.DateTime startTime = System.DateTime.UtcNow;
-
            Bounds bounds = o.bounds;

+           // Bounding rectangle with floating point coordinates
            Rect r = Rect.MinMaxRect (bounds.min.x,bounds.min.z,bounds.max.x,bounds.max.z);

+           // Bounding rectangle with int coordinates
            var r2 = new IntRect(
                Mathf.FloorToInt(bounds.min.x*Int3.Precision),
                Mathf.FloorToInt(bounds.min.z*Int3.Precision),
@@ -596,11 +595,16 @@ and have a low memory footprint because of their smaller size to describe the sa
                Mathf.FloorToInt(bounds.max.z*Int3.Precision)
            );

+           // Corners of the bounding rectangle
            var a = new Int3(r2.xmin,0,r2.ymin);
            var b = new Int3(r2.xmin,0,r2.ymax);
            var c = new Int3(r2.xmax,0,r2.ymin);
            var d = new Int3(r2.xmax,0,r2.ymax);

+           var ymin = ((Int3)bounds.min).y;
+           var ymax = ((Int3)bounds.min).y;
+
+           // Loop through all nodes
            graph.GetNodes (_node => {
                var node = _node as TriangleMeshNode;

@@ -611,8 +615,8 @@ and have a low memory footprint because of their smaller size to describe the sa
                int allTop = 0;
                int allBottom = 0;

+               // Check bounding box rect in XZ plane
                for (int v=0;v<3;v++) {
-
                    Int3 p = node.GetVertex(v);
                    var vert = (Vector3)p;

@@ -626,13 +630,15 @@ and have a low memory footprint because of their smaller size to describe the sa
                    if (vert.z < r.yMin) allTop++;
                    if (vert.z > r.yMax) allBottom++;
                }
+
                if (!inside) {
                    if (allLeft == 3 || allRight == 3 || allTop == 3 || allBottom == 3) {
                        return true;
                    }
                }

-               for (int v=0;v<3;v++) {
+               // Check if the polygon edges intersect the bounding rect
+               for (int v = 0; v < 3; v++) {
                    int v2 = v > 1 ? 0 : v+1;

                    Int3 vert1 = node.GetVertex(v);
@@ -644,7 +650,8 @@ and have a low memory footprint because of their smaller size to describe the sa
                    if (Polygon.Intersects (d,b,vert1,vert2)) { inside = true; break; }
                }

-               if (node.ContainsPoint (a) || node.ContainsPoint (b) || node.ContainsPoint (c) || node.ContainsPoint (d)) {
+               // Check if the node contains any corner of the bounding rect
+               if (inside || node.ContainsPoint (a) || node.ContainsPoint (b) || node.ContainsPoint (c) || node.ContainsPoint (d)) {
                    inside = true;
                }

@@ -652,6 +659,22 @@ and have a low memory footprint because of their smaller size to describe the sa
                    return true;
                }

+               int allAbove = 0;
+               int allBelow = 0;
+
+               // Check y coordinate
+               for (int v = 0; v < 3; v++) {
+                   Int3 p = node.GetVertex(v);
+                   var vert = (Vector3)p;
+                   if (vert.y < ymin) allBelow++;
+                   if (vert.y > ymax) allAbove++;
+               }
+
+               // Polygon is either completely above the bounding box or completely below it
+               if (allBelow == 3 || allAbove == 3) return true;
+
+               // Triangle is inside the bounding box!
+               // Update it!
                o.WillUpdateNode(node);
                o.Apply (node);
                return true;