diff --git a/package.json b/package.json
index 7066786..ceaeb95 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,14 @@
     {
       "name": "Philippe Rivière",
       "url": "https://visionscarto.net"
+    },
+    {
+      "name": "Enrico Spinielli",
+      "url": "https://enrico.spinielli.net/"
+    },
+    {
+      "name": "Ronnie Bathoorn",
+      "url": "https://github.com/bathoorn"
     }
   ],
   "type": "module",
diff --git a/src/polyhedral/butterfly.js b/src/butterfly.js
similarity index 85%
rename from src/polyhedral/butterfly.js
rename to src/butterfly.js
index 051fa68..68f1e9b 100644
--- a/src/polyhedral/butterfly.js
+++ b/src/butterfly.js
@@ -1,7 +1,7 @@
 import {geoCentroid as centroid, geoGnomonic as gnomonic} from "d3-geo";
-import {pi} from "../math.js";
-import polyhedral from "./index.js";
-import octahedron from "./octahedron.js";
+import {pi} from "./math.js";
+import polyhedral from "./polyhedral/index.js";
+import octahedron from "./polyhedral/octahedron.js";
 
 export default function(faceProjection = ((face) => {
   const c = centroid({type: "MultiPoint", coordinates: face});
diff --git a/src/collignon.js b/src/collignon.js
index 57f322f..e129e1e 100644
--- a/src/collignon.js
+++ b/src/collignon.js
@@ -1,6 +1,9 @@
-// code duplicated from d3-geo-projection
+import {geoCentroid as centroid, geoProjection as projection} from "d3-geo";
 import {asin, pi, sin, sqrt, sqrtPi} from "./math.js";
+import polyhedral from "./polyhedral/index.js";
+import octahedron from "./polyhedral/octahedron.js";
 
+// code duplicated from d3-geo-projection
 export function collignonRaw(lambda, phi) {
   const alpha = sqrt(1 - sin(phi));
   return [(2 / sqrtPi) * lambda * alpha, sqrtPi * (1 - alpha)];
@@ -10,3 +13,35 @@ collignonRaw.invert = function(x, y) {
   const lambda = (y / sqrtPi - 1);
   return [lambda ? x * sqrt(pi) / lambda / 2 : 0, asin(1 - lambda ** 2)];
 };
+
+
+const kx = 2 / sqrt(3);
+
+function collignonK(a, b) {
+  const p = collignonRaw(a, b);
+  return [p[0] * kx, p[1]];
+}
+
+collignonK.invert = (x,y) => collignonRaw.invert(x / kx, y);
+
+export default function(faceProjection = (face) => {
+  const c = centroid({type: "MultiPoint", coordinates: face});
+  return projection(collignonK).translate([0, 0]).scale(1).rotate(c[1] > 0 ? [-c[0], 0] : [180 - c[0], 180]);
+}) {
+  const faces = octahedron.map((face) => ({face, project: faceProjection(face)}));
+
+  [-1, 0, 0, 1, 0, 1, 4, 5].forEach((d, i) => {
+    const node = faces[d];
+    node && (node.children || (node.children = [])).push(faces[i]);
+  });
+
+  return polyhedral(
+    faces[0],
+    (lambda, phi) => faces[lambda < -pi / 2 ? phi < 0 ? 6 : 4
+            : lambda < 0 ? phi < 0 ? 2 : 0
+            : lambda < pi / 2 ? phi < 0 ? 3 : 1
+            : phi < 0 ? 7 : 5])
+    .angle(-30)
+    .scale(121.906)
+    .center([0, 48.5904]);
+}
diff --git a/src/cubic.js b/src/cubic.js
index 61122c6..82d6bb2 100644
--- a/src/cubic.js
+++ b/src/cubic.js
@@ -5,7 +5,21 @@
  *
  */
 import voronoi from "./polyhedral/voronoi.js";
-import { default as cube } from "./polyhedral/cube.js";
+import {atan, degrees, sqrt1_2} from "./math.js";
+
+const phi1 = atan(sqrt1_2) * degrees;
+const cube1 = [
+  [0, phi1], [90, phi1], [180, phi1], [-90, phi1],
+  [0, -phi1], [90, -phi1], [180, -phi1], [-90, -phi1]
+];
+const cube = [
+  [0, 3, 2, 1], // N
+  [0, 1, 5, 4],
+  [1, 2, 6, 5],
+  [2, 3, 7, 6],
+  [3, 0, 4, 7],
+  [4, 5, 6, 7] // S
+].map((face) => face.map((i) => cube1[i]));
 
 export default function() {
   const polygons = {
diff --git a/src/polyhedral/dodecahedral.js b/src/dodecahedral.js
similarity index 92%
rename from src/polyhedral/dodecahedral.js
rename to src/dodecahedral.js
index a6b0c0d..fcecfb6 100644
--- a/src/polyhedral/dodecahedral.js
+++ b/src/dodecahedral.js
@@ -1,5 +1,5 @@
-import {acos, asin, degrees, sqrt} from "../math.js";
-import voronoi from "./voronoi.js";
+import {acos, asin, degrees, sqrt} from "./math.js";
+import voronoi from "./polyhedral/voronoi.js";
 
 export default function() {
   const A0 = asin(1/sqrt(3)) * degrees;
diff --git a/src/index.js b/src/index.js
index 05175c1..d30a047 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,11 +1,11 @@
 export {default as geoClipPolygon} from "./clip/polygon.js";
 export {default as geoIntersectArc} from "./intersect.js";
 export {default as geoPolyhedral} from "./polyhedral/index.js";
-export {default as geoPolyhedralButterfly} from "./polyhedral/butterfly.js";
-export {default as geoPolyhedralCollignon} from "./polyhedral/collignon.js";
-export {default as geoPolyhedralWaterman} from "./polyhedral/waterman.js";
+export {default as geoPolyhedralButterfly} from "./butterfly.js";
+export {default as geoPolyhedralCollignon} from "./collignon.js";
+export {default as geoPolyhedralWaterman} from "./waterman.js";
 export {default as geoPolyhedralVoronoi} from "./polyhedral/voronoi.js";
-export {default as geoDodecahedral} from "./polyhedral/dodecahedral.js";
+export {default as geoDodecahedral} from "./dodecahedral.js";
 export {default as geoCox, coxRaw as geoCoxRaw} from "./cox.js";
 export {default as geoTetrahedralLee, leeRaw as geoLeeRaw} from "./tetrahedralLee.js";
 export {default as geoGrayFullerRaw} from "./grayfuller.js";
diff --git a/src/polyhedral/collignon.js b/src/polyhedral/collignon.js
deleted file mode 100644
index 8d3537d..0000000
--- a/src/polyhedral/collignon.js
+++ /dev/null
@@ -1,36 +0,0 @@
-import {geoCentroid as centroid, geoProjection as projection} from "d3-geo";
-import {collignonRaw} from "../collignon.js";
-import {pi, sqrt} from "../math.js";
-import polyhedral from "./index.js";
-import octahedron from "./octahedron.js";
-
-const kx = 2 / sqrt(3);
-
-function collignonK(a, b) {
-  const p = collignonRaw(a, b);
-  return [p[0] * kx, p[1]];
-}
-
-collignonK.invert = (x,y) => collignonRaw.invert(x / kx, y);
-
-export default function(faceProjection = (face) => {
-  const c = centroid({type: "MultiPoint", coordinates: face});
-  return projection(collignonK).translate([0, 0]).scale(1).rotate(c[1] > 0 ? [-c[0], 0] : [180 - c[0], 180]);
-}) {
-  const faces = octahedron.map((face) => ({face, project: faceProjection(face)}));
-
-  [-1, 0, 0, 1, 0, 1, 4, 5].forEach((d, i) => {
-    const node = faces[d];
-    node && (node.children || (node.children = [])).push(faces[i]);
-  });
-
-  return polyhedral(
-    faces[0],
-    (lambda, phi) => faces[lambda < -pi / 2 ? phi < 0 ? 6 : 4
-            : lambda < 0 ? phi < 0 ? 2 : 0
-            : lambda < pi / 2 ? phi < 0 ? 3 : 1
-            : phi < 0 ? 7 : 5])
-    .angle(-30)
-    .scale(121.906)
-    .center([0, 48.5904]);
-}
diff --git a/src/polyhedral/cube.js b/src/polyhedral/cube.js
deleted file mode 100644
index 97969ee..0000000
--- a/src/polyhedral/cube.js
+++ /dev/null
@@ -1,17 +0,0 @@
-import {atan, degrees, sqrt1_2} from "../math.js";
-
-const phi1 = atan(sqrt1_2) * degrees;
-
-const cube = [
-  [0, phi1], [90, phi1], [180, phi1], [-90, phi1],
-  [0, -phi1], [90, -phi1], [180, -phi1], [-90, -phi1]
-];
-
-export default [
-  [0, 3, 2, 1], // N
-  [0, 1, 5, 4],
-  [1, 2, 6, 5],
-  [2, 3, 7, 6],
-  [3, 0, 4, 7],
-  [4, 5, 6, 7] // S
-].map((face) => face.map((i) => cube[i]));
diff --git a/src/polyhedral/waterman.js b/src/waterman.js
similarity index 96%
rename from src/polyhedral/waterman.js
rename to src/waterman.js
index 2070a69..b741885 100644
--- a/src/polyhedral/waterman.js
+++ b/src/waterman.js
@@ -1,7 +1,7 @@
 import {geoCentroid as centroid, geoGnomonic as gnomonic} from "d3-geo";
-import {asin, atan2, cos, degrees, max, min, pi, radians, sin} from "../math.js";
-import polyhedral from "./index.js";
-import octahedron from "./octahedron.js";
+import {asin, atan2, cos, degrees, max, min, pi, radians, sin} from "./math.js";
+import polyhedral from "./polyhedral/index.js";
+import octahedron from "./polyhedral/octahedron.js";
 
 export default function(faceProjection = ((face) => {
   const c = face.length === 6 ? centroid({type: "MultiPoint", coordinates: face}) : face[0];