Is the 3D Preview an accurate representation of the shape?
Hyperstudio was not designed to show 3D models. The original Shape Magic did not have a 3D preview and it was only after the model was imported into Bryce, Vue or Poser that its design could be fully checked. Shape Magic 2 has a 3D preview made by drawing closely spaced thick lines around the model. The color changes depending upon the x,y,z position. This gives you a psuedo-3D view of the shape which will allow you to make changes before saving the file.