Protopiper Lets You Sketch Full-Size Objects In Real Space
Protopiper is an intriguing device that lets you sketch three-dimensional objects in real time. It's a kind of 3d printing - freehand.
Protopiper is a computer aided, hand-held fabrication device that allows users to sketch room-sized objects at actual scale. The key idea behind protopiper is that it forms adhesive tape into tubes as its main building material, rather than extruded plastic or photopolymer lines. Since the resulting tubes are hollow they offer excellent strength-to-weight ratio, thus scale well to large structures.
The earliest sf reference that I know of for creating a 3D object with a penlike device is from Things Pass By, a 1945 story by Murray Leinster:
It makes drawings in the air following drawings it scans with photo-cells. But plastic comes out of the end of the drawing arm and hardens as it comes. This thing will start at one end of a ship or a house and build it complete to the other end, following drawings only.
(Read more about Leinster's Plastic Constructor)