Interactive pop-up card design. 2

Pop-up cards are fun to create and receive. They´re also a great output medium for computer graphics, offering an economic and compact way to show 3D scenes without the need for special glasses, shutters or any other electronic hardware. Two basic pop-up mechanisms - the single-slit and the V-fold - are the heart of my interactive pop-up design assistant, which I use to design cards on the computer that I then print out and assemble. Happily, these two mechanisms are also among the most general of all techniques used in pop-ups, since many of the other constructions are combinations of these mechanisms or variations on their geometry. Of course, a variety of pop-up mechanisms exist that aren´t captured by those ideas. Happily, most of those are straightforward to design and create with special-purpose code and don´t present the sort of design challenges that the slit and V-fold designs do