Make your own action figures with a 3-D printer

Aug 29, 2012 by Bill Steele
Make your own action figures with a 3-D printer
An articulated model based on a 3-D scan of a human hand. Above,the steps in creating a model: The computer divides the 3-D image into segments, decides where to pace joints and adds the joints to the design, which a 3-D printer fabricates in plastic.

Computer graphics researchers at Cornell and Harvard have created software that will translate a graphic image of a character from a movie or video game, or even something you've created yourself, into a posable plastic model manufactured by a 3-D printer. Eventually this capability might be built into games and other software, the researchers said.

The project by Moritz Bächer and Hanspeter Pfister of Harvard, Bernd Bickel of the Technische Universität Berlin, and Doug James, Cornell associate professor of computer science, was described at the SIGGRAPH conference Aug. 7 in Los Angeles and in the July 2012 issue of the Association for Computing Machinery journal Transactions on Graphics. The researchers displayed models they had made of characters created in the video game "Spore," which allows the player to evolve an alien creature, as well as an articulated model of a human hand.

A 3-D printer builds a solid object by scanning across a table and depositing tiny droplets of plastic or another material, then moving upward in tiny steps to add additional layers. Professional 3-D printers, used in industry for prototyping machinery, sell for $50,000 and up. The researchers suggest that character printing might be offered as an online service or perhaps as a service by hobby stores.

In a game or movie all the computer knows about a character is the overall shape. "All previous work on printing characters has just made solid shapes. Ours makes an articulated model," said James, who is a specialist on the animation of what the industry calls "skinned characters."

An alien created in the Spore and fabricated by a 3-D printer.

Make your own action figures with a 3-D printer
An alien created in the video game Spore and fabricated by a 3-D printer.

The computer represents the skin as a lot of tiny triangles linked together. By examining the angles between the triangles it can find the bends. In effect it imagines a skeleton and figures out where joints should go. The user enters the process here, specifying which kind of joint to use. Elbows and knees get hinges. Torsos, tails and perhaps tentacles get ball and socket joints with what engineers call "three degrees of freedom."

The computer has a built-in description for each type of joint but must find the right size. The joint must be strong enough to support a particular part of the body, but "It might make the joint really huge so it sticks out through the skin, or collides with other joints, or it might be too small to print, so our algorithm has an optimization step to find the best balance," James explained. Finally, small bumps are added to the joint parts to create friction so that the figure will hold a pose.

To print a joint with moving parts, the 3-D printer deposits two different materials: a plastic that forms solid parts of the figure, and a temporary material that fills in what will eventually be empty spaces. This holds the figure together during printing, but the filler essentially turns to dust when the finished figure is first moved.

The software still needs refinements to handle some types of joints, the researchers said, and adding a flexible skin to cover the joints is a possible improvement. Some day, James suggested, it might be possible to build in motors and other actuators to create robotic figures that could "walk out of the printer when they're ready."

The work has been partially supported by the National Science Foundation. James received support from a Guggenheim fellowship and from Pixar. Test figures were printed at Disney Research Boston.

Explore further: Faster computation of electromagnetic interference on an electronic circuit board

Related Stories

New file format will help 3-D printing progress

Jul 22, 2011

( -- A newly approved standard for 3-D printing file interchange will greatly enhance 3-D printing capabilities, says Cornell's Hod Lipson, who led the development of the standard.

Cebit 2012: 3-D animations for everyone

Mar 06, 2012

3D movies like "Toy Story" or "Transformers" are based on everyday objects that are able to move like humans. Such 3D characters are created by skilled experts in time-consuming manual work. Computer scientists ...

Researchers develop new physical face cloning method

Aug 10, 2012

Animatronics aims at creating physical robots that move and look like real humans. Many impressive characters have been created in this spirit, like those in the Hall of Presidents attraction at Walt Disney ...

Recommended for you

A smart prosthetic knee with in-vivo diagnoses

Apr 22, 2014

The task was to develop intelligent prosthetic joints that, via sensors, are capable of detecting early failure long before a patient suffers. EPFL researchers have taken up the challenge.

Old tires become material for new and improved roads

Apr 22, 2014

( —Americans generate nearly 300 million scrap tires every year, according to the Environmental Protection Agency (EPA). Historically, these worn tires often end up in landfills or, when illegally ...

Students take clot-buster for a spin

Apr 21, 2014

( —In the hands of some Rice University senior engineering students, a fishing rod is more than what it seems. For them, it's a way to help destroy blood clots that threaten lives.

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Aug 29, 2012
Someone really needs to start a 3d printing business. I'm sure there are millions of things that can already be printed that people would happily pay for.
Spore creatures for one - I would have paid to have some of mine printed.
not rated yet Aug 29, 2012
They need to add functionality similar to normal 2D printers. Its good that 3D printers can sculpt stuff but they need to paint them too.
1 / 5 (2) Aug 29, 2012
Someone really needs to start a 3d printing business. I'm sure there are millions of things that can already be printed that people would happily pay for.
Spore creatures for one - I would have paid to have some of mine printed.

There is a company that's been printing and hand painting world of warcraft characters for years... I consider having it done when I was 2nd ranked warlock on the server in WOTLK, but maturity got the better of me and I stopped spending all my time on that game instead.
1.8 / 5 (21) Aug 29, 2012
Laika (formerly Will Vinton Studios), an animation company in Oregon has just released a film using 3d printed characters and thousands of pieces of characters. It doesn't use the joint technology, but the result are quite realistic.

More news stories

Amazon Prime wins streaming deal with HBO

Amazon scored a deal Wednesday to distribute old shows from premium cable TV channel HBO to its monthly Prime subscribers, landing a blow on rival Netflix in the streaming video battle.

Is nuclear power the only way to avoid geoengineering?

"I think one can argue that if we were to follow a strong nuclear energy pathway—as well as doing everything else that we can—then we can solve the climate problem without doing geoengineering." So says Tom Wigley, one ...

Robot scouts rooms people can't enter

( —Firefighters, police officers and military personnel are often required to enter rooms with little information about what dangers might lie behind the door. A group of engineering students at ...

Cyber buddy is better than 'no buddy'

A Michigan State University researcher is looking to give exercise enthusiasts the extra nudge they need during a workout, and her latest research shows that a cyber buddy can help.