diff --git a/src/voxel/_impl/_vx_from_impl.scad b/src/voxel/_impl/_vx_from_impl.scad
index e7adc30b..fcf2966e 100644
--- a/src/voxel/_impl/_vx_from_impl.scad
+++ b/src/voxel/_impl/_vx_from_impl.scad
@@ -4,9 +4,10 @@ function _vx_from_row(r_count, row_bits, width, height, center, invert) =
         half_h = height / 2,
         offset_x = center ? 0 : half_w,
         offset_y = center ? -half_h : 0,
-        bit = invert ? 0 : 1
+        bit = invert ? 0 : 1,
+        y = r_count + offset_y
     ) 
-    [for(i = 0; i < width; i = i + 1) if(row_bits[i] == bit) [i - half_w + offset_x, r_count + offset_y]];
+    [for(i = 0; i < width; i = i + 1) if(row_bits[i] == bit) [i - half_w + offset_x, y]];
 
 function _vx_from_impl(binaries, center, invert) = 
     let(
diff --git a/src/voxel/_impl/_vx_gray_impl.scad b/src/voxel/_impl/_vx_gray_impl.scad
index fa54e3da..fa8db8de 100644
--- a/src/voxel/_impl/_vx_gray_impl.scad
+++ b/src/voxel/_impl/_vx_gray_impl.scad
@@ -5,15 +5,16 @@ function _vx_gray_row(r_count, row_bits, width, height, center, invert, normaliz
         offset_x = center ? 0 : half_w,
         offset_y = center ? -half_h : 0,
         level = invert ? 0 : 255,
-        nmal = normalize ? 255 : 1
+        nmal = normalize ? 255 : 1,
+        y = r_count + offset_y
     ) 
     [
         for(i = 0; i < width; i = i + 1) 
-            if(row_bits[i] != level) 
-                [
-                    [i - half_w + offset_x, r_count + offset_y], 
-                    invert ? row_bits[i] / nmal : (255 - row_bits[i]) / nmal
-                ]
+        if(row_bits[i] != level) 
+        [
+            [i - half_w + offset_x, y], 
+            invert ? row_bits[i] / nmal : (255 - row_bits[i]) / nmal
+        ]
     ];
 
 function _vx_gray_impl(levels, center, invert, normalize) = 
diff --git a/src/voxel/vx_polygon.scad b/src/voxel/vx_polygon.scad
index f74fa0ac..1d4ec30b 100644
--- a/src/voxel/vx_polygon.scad
+++ b/src/voxel/vx_polygon.scad
@@ -11,18 +11,16 @@ function vx_polygon(points, filled = false) =
         ys = [for(p = sortedXY) p.y],
         rows = [
             for(y = [min(ys):max(ys)])
-            let(
-                idxes = search(y, sortedXY, num_returns_per_match = 0, index_col_num = 1)
-            )
+            let(idxes = search(y, sortedXY, num_returns_per_match = 0, index_col_num = 1))
             [for(i = idxes) sortedXY[i]]
         ],
         all = concat(
             sortedXY,
             [
                 for(row = rows)
-                let(to = len(row) - 1, row0 = row[0], y = row0[1])
-                if(to > 0 && (row0[0] + 1 != row[to][0]))
-                    for(i = [row0[0] + 1:row[to][0] - 1])
+                let(to = len(row) - 1, row0 = row[0], y = row0[1], row_to = row[to])
+                if(to > 0 && (row0[0] + 1 != row_to[0]))
+                    for(i = [row0[0] + 1:row_to[0] - 1])
                     let(p = [i, y])
                     if(in_shape(points, p)) p
             ]
diff --git a/src/voxel/vx_sphere.scad b/src/voxel/vx_sphere.scad
index 45c7dd66..b62b379f 100644
--- a/src/voxel/vx_sphere.scad
+++ b/src/voxel/vx_sphere.scad
@@ -13,15 +13,15 @@ function vx_sphere(radius, filled = false, thickness = 1) =
     filled ? [
         for(z = range, y = range, x = range)
         let(v = [x, y, z])
-        if(norm(v) < radius) v
+        if(v * v < radius ^ 2) v
     ] :
     let(ishell = radius * radius - 2 * thickness * radius)
     [
         for(z = range, y = range, x = range)
         let(
             v = [x, y, z],
-            leng = norm(v)
+            vv = v * v
         )
-        if(leng < radius && (leng * leng) > ishell) v    
+        if(vv < radius ^ 2 && vv > ishell) v    
     ];
     
\ No newline at end of file