diff --git a/assets/index.html b/assets/index.html
index fc5e3af..61aa0a8 100644
--- a/assets/index.html
+++ b/assets/index.html
@@ -196,10 +196,10 @@
 
             if (h > 0) {
                 var hRightNeighbor = heightMap[(wx + TILE) + ',' + wy] || 0;
-                var hLeftNeighbor = heightMap[wx + ',' + (wy - TILE)] || 0;
+                var hBackNeighbor = heightMap[wx + ',' + (wy - TILE)] || 0;
 
                 var shadowFromRight = hRightNeighbor - h;
-                var shadowFromLeft = hLeftNeighbor - h;
+                var shadowFromBack = hBackNeighbor - h;
 
                 if (shadowFromRight > 0) {
                     var shadowW = Math.min(shadowFromRight * 2, TILE);
@@ -221,13 +221,13 @@
                     });
                 }
 
-                if (shadowFromLeft > 0) {
-                    var shadowW = Math.min(shadowFromLeft * 2, TILE);
+                if (shadowFromBack > 0) {
+                    var shadowW = Math.min(shadowFromBack * 2, TILE);
                     var tt = shadowW / TILE;
                     var top1 = project(wx + GAP/2, wy + TILE - GAP/2, h * HEIGHT_UNIT);
-                    var top4 = project(wx + GAP/2, wy + GAP/2, h * HEIGHT_UNIT);
+                    var top2 = project(wx + TILE - GAP/2, wy + TILE - GAP/2, h * HEIGHT_UNIT);
                     var topA = project(wx + GAP/2, wy + TILE - GAP/2 - (TILE - GAP) * tt, h * HEIGHT_UNIT);
-                    var topB = project(wx + GAP/2, wy + GAP/2 - (TILE - GAP) * tt, h * HEIGHT_UNIT);
+                    var topB = project(wx + TILE - GAP/2, wy + TILE - GAP/2 - (TILE - GAP) * tt, h * HEIGHT_UNIT);
 
                     renderList.push({
                         type: 'shadow',
@@ -235,7 +235,7 @@
                             { x: top1[0], y: top1[1] },
                             { x: topA[0], y: topA[1] },
                             { x: topB[0], y: topB[1] },
-                            { x: top4[0], y: top4[1] }
+                            { x: top2[0], y: top2[1] }
                         ],
                         depth: wx + wy + 0.0005
                     });