diff --git a/js/geo-polygons.js b/js/geo-polygons.js
index ec2c0c1e..41faac4b 100644
--- a/js/geo-polygons.js
+++ b/js/geo-polygons.js
@@ -422,7 +422,9 @@ var gs_base_polygons = exports;
 
         if (out) out.appendAll(polys);
         if (collector) collector(polys, count);
-        if ((count === 0 || count > 1) && polys.length > 0) expand(polys, distance2 || distance, z, out, count > 0 ? count-1 : 0, distance2, collector);
+        if ((count === 0 || count > 1) && polys.length > 0) {
+            expand(polys, distance2 || distance, z, out, count > 0 ? count-1 : 0, distance2, collector);
+        }
 
         return polys;
     }
diff --git a/js/kiri-slice.js b/js/kiri-slice.js
index bb15183c..e440f127 100644
--- a/js/kiri-slice.js
+++ b/js/kiri-slice.js
@@ -82,11 +82,11 @@ var gs_kiri_slice = exports;
      */
     function Top(polygon) {
         this.poly = polygon; // outline poly
-        this.traces = null; // array of offset/inset trace polygons
-        this.inner = null; // array of inner fillable polygon areas (inside last trace)
-        this.outer = null; // array of outer trace polygons
-        this.fill_lines = null; // array of solid fill lines
-        this.fill_sparse = null; // array of sparse fill polygons
+        this.traces = null; // array of offset/inset trace polygons (ordered outer to inner)
+        this.inner = null; // array of inner fillable areas (inset from last trace)
+        this.outer = null; // array of outer trace polygons (TODO remove)
+        this.fill_lines = null; // solid fill lines (array of points)
+        this.fill_sparse = null; // sparse fill area open polygons (poly lines)
         this.solids = null; // solid fill regions in otherwise sparse fill (from solids.trimmed)
     }
 
@@ -178,7 +178,7 @@ var gs_kiri_slice = exports;
     };
 
     /**
-     * Appends all top polygons into a given array and returns it
+     * Returns all top polygons as an array
      *
      * @param {Polygon[]} out array to populate
      * @returns {Polygon[]} array of top polygons
@@ -375,13 +375,17 @@ var gs_kiri_slice = exports;
                     last = [top.poly].clone(true);
                     top.traces = last;
                 } else {
-                    POLY.expand([top.poly], -offset1, top.poly.getZ(), top.traces, count, -offsetN, function(polys, count2) {
-                        if (count === count2) top.outer = polys;
+                    POLY.expand([top.poly], -offset1, top.poly.getZ(), top.traces, count, -offsetN, function(polys, countNow) {
+                        // first offset is the outer poly group (max count #)
+                        if (count === countNow) top.outer = polys;
                         last = polys;
+                        // mark each poly with depth (offset #) starting at 0
+                        polys.forEach(function(p) { p.depth = count - countNow });
                     });
                 }
             }
 
+            // generate fill offset poly set from last offset to top.inner
             if (fillOffset && last.length > 0) {
                 last.forEach(function(inner) {
                     POLY.trace2count(inner, top.inner, fillOffset, 1, 0);
diff --git a/package.json b/package.json
index 712574b6..8a7f654a 100644
--- a/package.json
+++ b/package.json
@@ -34,9 +34,9 @@
         "express-useragent": "^1.0.8",
         "leveldown": "^1.9.0",
         "levelup": "^1.3.9",
-        "moment": "^2.19.1",
+        "moment": "^2.19.3",
         "n3d-threejs": "^72.0.0",
-        "pixi.js": "^4.6.0",
+        "pixi.js": "^4.6.2",
         "request": "^2.83.0",
         "serve-static": "^1.13.1",
         "tween.js": "^0.14.0",