Researchers at Cornell University have launched EndlessForms, a website that lets users create sculptures virtually and render them in physical form. The site demonstrates a technology that designers could use to create new products and accelerate the broader adoption of 3-D printing.

People can use EndlessForms without any prior 3-D design experience. The user begins by choosing an object from a randomly generated gallery. The site creates a new gallery of variants of the chosen object, and the user selects one of the variants. The process repeats, gradually refining the design into the shape the user desires. Users can share this shape with other users and, if they wish, send the object to a 3-D printing service to render it in a variety of materials, including plastic, silver, and gold-plated steel. A five-to-seven-centimeter plastic model typically costs less than $10.

Jeff Clune, a postdoctoral fellow at Cornell and the project lead, believes this approach is a critical advance over earlier attempts to produce objects and shapes through digital mutation and selection. Those attempts produced things that "just don't look that natural," says Clune. "So we went and stole the secrets that biological evolution took millions of years to discover." According to Clune, generating objects in this way automatically gives them useful properties such as symmetry, and when these objects are printed in 3-D, they usually turn out to be structurally sound.

The rules EndlessForms uses to generate objects and their variants resemble those of developmental biology—the study of how DNA instructions unfold to create an entire living organism. "Embryos create patterns in the form of chemical gradients," says Clune. Chemical gradients—changes in the concentrations of particular molecules—control which parts of an embryonic organism's genome are expressed. "There might be a simple linear gradient, like head to tail, or there might be might be a repeating gradient, like that which governs the creation of segments in a caterpillar," says Clune. Combining a head-to-tail, front-to-back, and repeating gradient, for example, creates the basic body plan of vertebrates.