Models are javascript code -- use your browser's view source mode (often ctrl-u, or prepend view-source: to the URL on mobile) on the demos to see the code that generates the demo models. When viewing the HTML files in a browser, you can adjust the parameters of the model before running it to generate the geometry of the object. To make your own object or hack on one of the demos, save nt3d.js and one of the demo .html files locally, edit the .html file with your favorite text editor, and view it in a browser (eg: with a file:/// URL, or try just opening it from your file browser). Your web browser is now 3D-modeling software, no 'net connection required!
