const truncatedVertices = duplicated.vertices.map(vertex => {
   const adjacentVertices = vertex.adjacentVertices();
   const v = vertex.vec;
   const v1 = find(adjacentVertices, adj => adj.vec.distanceTo(v) > PRECISION);
   const truncated = v.interpolateTo(v1.vec, rectify ? 0.5 : truncateScale);
   return !!transform ? transform(truncated, vertex) : truncated;
 });

 return (vector, vertex) => {
   const smallFace = find(vertex.adjacentFaces(), {
     numSides: 6,
   });
   const normal = smallFace.withPolyhedron(polyhedron).normal();
   const transform = withOrigin(smallFace.centroid(), v =>
     v
       .scale(faceResizeScale)
       .add(normal.scale(normalizedResizeAmount * newSideLength)),
   );
   return transform(vector);
 };

export function getChirality(polyhedron: Polyhedron) {
  const [cap1, cap2] = Cap.getAll(polyhedron);
  const boundary = cap1.boundary();
  const isCupolaRotunda = cap1.type !== cap2.type;

  const nonTriangleFace = find(boundary.edges, e => e.face.numSides !== 3);
  const rightFaceAcross = nonTriangleFace
    .twin()
    .prev()
    .twin()
    .next()
    .twin().face;
  // I'm pretty sure this is the same logic as in augment
  if (isCupolaRotunda) {
    return rightFaceAcross.numSides !== 3 ? 'right' : 'left';
  }
  return rightFaceAcross.numSides !== 3 ? 'left' : 'right';
}

 prevEdge(e: Edge) {
   return find(this.edges, e2 => e2.v2.equals(e.v1));
 }

 nextEdge(e: Edge) {
   return find(this.edges, e2 => e2.v1.equals(e.v2));
 }