diff --git a/src/pg/sql/12_contour2.sql b/src/pg/sql/12_contour2.sql
index 7e6ac28..9b07d92 100644
--- a/src/pg/sql/12_contour2.sql
+++ b/src/pg/sql/12_contour2.sql
@@ -1,13 +1,3 @@
--- =============================================================================================
---
--- CDB_Contour v2
---
--- Meander triangles
---
--- author: Abel Vázquez
---
--- =============================================================================================
-
 CREATE OR REPLACE FUNCTION CDB_contour2(
     IN geomin geometry[],
     IN colin numeric[],
@@ -30,8 +20,10 @@ DECLARE
     interp31 geometry[];
     segment geometry[];
     running_merge geometry[];
-    -- interlines geometry;
     geomout geometry;
+    i integer;
+    cell_breaks integer[];
+    running_breaks integer[];
 BEGIN
 
     -- generate the breaks
@@ -56,6 +48,9 @@ BEGIN
         c as (SELECT (ST_Dump(t)).geom AS v FROM b)
     SELECT array_agg(v) INTO gs FROM c;
 
+    -- RAISE NOTICE 'TIN size: %',array_length(gs,1);
+    i:= 0;
+
     -- ======================================================================================
 
     -- loop in the TIN
@@ -74,89 +69,133 @@ BEGIN
         WITH a AS(SELECT unnest(geomin) as geo, unnest(colin) as c)
         SELECT c INTO v3 FROM a WHERE ST_Equals(geo, vertex[3]);
 
+        -- RAISE NOTICE 'Cell: %', i;
+        -- i := i +1;
+
         -- retrieve the bucket index of each vertex
         bu := ARRAY[width_bucket(v1, breaks), width_bucket(v2, breaks), width_bucket(v3, breaks)];
 
+        -- RAISE NOTICE ' - BU: %',bu;
+
         -- continue when there is no contour line crossing the current cell
         CONTINUE WHEN bu[1] = bu[2] and bu[1] = bu[3];
 
         -- we have contour lines in this cell, let's find their intersections with triangle sides
+        interp12 := array_fill(null::geometry, ARRAY[steps]);
         IF bu[1] <> bu[2] THEN
             SELECT array_agg((t.x-v1)/(v2-v1)) INTO inter FROM unnest(breaks) as t(x);
+            -- RAISE NOTICE ' - Inter 12: %', inter;
+
             WITH a as(
                 SELECT
-                    ST_Line_Interpolate_Point(ST_MakeLine(vertex[1], vertex[2]),t.x)
+                    CASE WHEN t.x BETWEEN 0 AND 1 THEN
+                    ST_LineInterpolatePoint(ST_MakeLine(vertex[1], vertex[2]),t.x)
+                    ELSE null::geometry END as point
                 FROM unnest(inter) as t(x)
-                WHERE t.x BETWEEN 0 AND 1
             )
             SELECT
-                array_agg(g) INTO interp12
+                array_agg(point) INTO interp12
             FROM a;
         END IF;
 
+        interp23 := array_fill(null::geometry, ARRAY[steps]);
         IF bu[2] <> bu[3] THEN
             SELECT array_agg((t.x-v2)/(v3-v2)) INTO inter FROM unnest(breaks) as t(x);
+            -- RAISE NOTICE ' - Inter 23: %', inter;
+
             WITH a as(
                 SELECT
-                    ST_Line_Interpolate_Point(ST_MakeLine(vertex[2], vertex[3]),t.x)
+                    CASE WHEN t.x BETWEEN 0 AND 1 THEN
+                    ST_LineInterpolatePoint(ST_MakeLine(vertex[2], vertex[3]),t.x)
+                    ELSE null::geometry END as point
                 FROM unnest(inter) as t(x)
-                WHERE t.x BETWEEN 0 AND 1
             )
             SELECT
-                array_agg(g) INTO interp23
+                array_agg(point) INTO interp23
             FROM a;
         END IF;
 
+        interp31 := array_fill(null::geometry, ARRAY[steps]);
         IF bu[3] <> bu[1] THEN
             SELECT array_agg((t.x-v3)/(v1-v3)) INTO inter FROM unnest(breaks) as t(x);
+            -- RAISE NOTICE ' - Inter 31: %', inter;
+
             WITH a as(
                 SELECT
-                    ST_Line_Interpolate_Point(ST_MakeLine(vertex[3], vertex[1]),t.x)
+                    CASE WHEN t.x BETWEEN 0 AND 1 THEN
+                    ST_LineInterpolatePoint(ST_MakeLine(vertex[3], vertex[1]),t.x)
+                    ELSE null::geometry END as point
                 FROM unnest(inter) as t(x)
-                WHERE t.x BETWEEN 0 AND 1
             )
             SELECT
-                array_agg(g) INTO interp31
+                array_agg(point) INTO interp31
             FROM a;
         END IF;
 
-        -- create segments per bucket
+        -- create segments crossing the cell per bucket
         WITH
         a as(
             SELECT
+            generate_series(1,steps) as break,
             unnest(interp12) as p12,
             unnest(interp23) as p23,
             unnest(interp31) as p31
         ),
         b as(
             SELECT
+                break,
                 ST_MakeLine(ARRAY[p12, p23, p31]::geometry[]) as segm
             FROM a
+            WHERE
+                (p12 is not null and p23 is not null and ST_equals(p12, p23)=false) OR
+                (p23 is not null and p31 is not null and ST_equals(p23, p31)=false) OR
+                (p31 is not null and p12 is not null and ST_equals(p31, p12)=false)
         )
         SELECT
-            array_agg(segm) INTO segment
+            array_agg(break), array_agg(segm) INTO cell_breaks, segment
         FROM b
         WHERE
             segm IS NOT null AND
             ST_IsEmpty(segm) = false;
 
-        -- concat the segments
-        SELECT
-            CASE
-            WHEN array_length(running_merge,1)=0 THEN segment
-            ELSE array_cat(running_merge, segment) END
-        INTO running_merge;
+        -- RAISE NOTICE ' - Segments: %',array_length(segment,1);
+
+        -- concat the segments and breaks
+        IF array_length(running_merge,1)=0 THEN
+            running_merge := segment;
+            running_breaks := cell_breaks;
+        ELSE
+            running_merge := running_merge || segment ;
+            running_breaks := running_breaks || cell_breaks;
+        END IF;
 
     -- loop end
     END LOOP;
 
-    segment := unnest(running_merge);
-    RETURN ST_Collect(segment);
-
+    -- RAISE NOTICE 'TOTAL segment: %',array_length(running_merge,1);
 
     -- ======================================================================================
 
-    -- merge and polygonize the results
+    running_merge := running_merge || ST_ExteriorRing(ST_Convexhull(ST_Collect(geomin))) ;
+
+    WITH
+    a as(
+     SELECT unnest(running_merge) as geo
+    )
+    SELECT ST_collect(geo) into geomout from a;
+
+    -- return some stuff
+    RETURN geomout;
+
+END;
+$$ language plpgsql IMMUTABLE;
+
+
+
+-- ////////////////////////////////////////////////////////////
+
+-- merge and polygonize the results
+
     WITH
     partials as(
         SELECT
@@ -197,8 +236,27 @@ BEGIN
         ST_GeometryType(geo) = 'ST_Polygon';
 
 
-    -- return some stuff
-    RETURN geomout;
+-- ////////////////////////////////////////////////////////////
 
-END;
-$$ language plpgsql IMMUTABLE;
+
+with
+a as(
+  SELECT
+  array_agg(the_geom) as geomin,
+  array_agg(real_capacity) as colin
+  FROM uk_fcc
+  ),
+b as(
+  SELECT
+      CDB_contour2(
+        geomin,
+        colin,
+        2,
+        7
+      ) as the_geom
+   from a
+  )
+  SELECT
+  *,
+  st_transform(the_geom::geometry, 3857) as the_geom_webmercator
+  from b;