ShapeJS script to create a Herschel enneahedron. Use with http://shapejs.shapeways.com/creator/. One argument: height scaling factor.

herschel.js

function herschel(h1,size) {
  var h2 = h1*4/3;
  
  var root3 = Math.sqrt(3);
  
  var vertices = [
    [1/2,0,-h1],
    [0,0,0],
    [1/2,0,h1],
    [1,0,0],
    [1/2, root3/6,-h2],
    [1/4,root3/4,-h1],
    [1/4,root3/4,h1],
    [1/2,root3/6,h2],
    [3/4,root3/4,h1],
    [3/4,root3/4,-h1],
    [1/2,root3/2,0]
  ];
  
  vertices = vertices.map(function(v) {
    return new Vector3d((v[0]-0.5)*size,(v[1]-root3/6)*size,v[2]*size);
  });
  
  var faces = [
    [1,7,2],
    [1,10,6],
    [6,8,7],
    [5,9,10],
    [10,3,8],
    [2,7,8],
    [1,4,5],
    [4,0,3],
    [1,3,0]
  ];
                          
  faces = faces.map(function(f) {
    return new Plane(vertices[f[0]],vertices[f[2]],vertices[f[1]]);
  });
  
  var int = new Intersection(faces[0],faces[1]);
  for(var i=2;i<faces.length;i++) {
    int.add(faces[i]);
  }
  
  return int;
}

function main(args) {
  var grid = createGrid(-16*MM,16*MM,-16*MM,16*MM,-16*MM,16*MM,0.1*MM);
  var shape = herschel(args[0],15*MM);
  var maker = new GridMaker();
  maker.setSource(shape);
  maker.makeGrid(grid);
  return grid;
}