Stanford researchers fine-tune 3-D fax machine

Article in San Jose Mercury News, February 5, 1996
by Jim Puzzanghera, Mercury News Staff Writer
© 1996 Mercury Center

Imagine that your young daughter has just come home with her first coffee mug from art class. It's kind of misshapen -- the handle's a little crooked, the sides aren't smooth and a couple of her fingerprints are baked into the pottery -- but she made it with her own little hands.

Although they live hundreds of miles away, you want her grandparents to see it. Not just a picture, but the actual mug in all its endearing detail.

So you open the door to your three-dimensional fax machine and send it to them.

They receive an identical 3-D image on their computer. Or better yet, depending on how far in the future this is, a special machine makes an exact duplicate in plastic that they can hold in their hand.

That future may not be as far off as you might think. Researchers at Stanford University's Computer Graphics Laboratory have demonstrated the ability to quickly make a highly detailed, three-dimensional computer model of an object, send it electronically to Southern California and use it to produce an almost exact duplicate.

It may be only fantasy to think that this technology some day will be in every home or office, the way conventional fax machines are now. But many fields could take advantage of the technology, said Marc Levoy, an assistant professor of computer science and electrical engineering and head of the 3-D fax project.

Archaeologists could analyze significant findings without traveling to the site of the dig, manufacturers such as automobile companies could duplicate a handcrafted engineering prototype, and movie studios could easily turn small models into amazing special effects, he said. Eventually, a laser scanner could be used to make images of more sprawling things, such as an entire oil refinery, to be used by architects or people trying to construct replacement parts for it.

Detailed three-dimensional computer models of complex objects are not new, but they've always been painstaking to produce, usually requiring somebody to digitize the entire surface of the object by touching every point on it with a special probe, Levoy said. It takes days to make a computer model that way.

``We want to simplify that -- take the model, stick it in a box the size of a microwave oven, shut the door, push a button and you'll have a computer model,'' he said.

One of top groups

Levoy's team is one of the top groups in the country working in this area, said Chris Johnson, a computer science professor at the University of Utah, which is renowned for its three-dimensional imaging work.

``There's just loads of great applications for the people who can really make this a working technology,'' he said.

Levoy and his team, which now includes engineering doctoral student Brian Curless and General Electric senior scientist Bill Lorensen, have been working for several years to do that -- to make the scanning process much quicker by using a laser and intricate computer programs.

``People have been working on this problem for 20 or more years,'' Levoy said. ``They've not met with a lot of success.''

Duplicating Buddha

But two weeks ago, the team took an intricate, 6-inch-high Buddha sculpture and used a laser range scanner to make a three-dimensional model in about six hours, taking 58 scans of the statue from different angles. The triangulated images were then used to create a computer-generated 3-D image made of 2.5 million polygons. It is the most complex computer model ever made from a physical model, Levoy said.

The computer model was then transmitted to 3-D Systems in Valencia, a company that used a commercial process called stereolithography to make an almost exact duplicate of the statue in a resin material. The company mailed it back to Stanford, and now Levoy proudly can hold the two statues side by side in the Computer Graphics Laboratory at the new Gates Computer Science Building on campus.

Pine-cone problem

On a corner of his desk are several things Levoy and his team have scanned into 3-D models, including a basketball sneaker and a toy dinosaur. He also has a large pine cone to remind him that some things are just too detailed to scan into three-dimensional images at this point.

During dedication ceremonies last week, the 3-D fax was one of several computer research projects shown to the building's chief donor and namesake, Microsoft Chairman Bill Gates. He and his wife Melissa donned special glasses to view the three-dimensional images generated by the lab's responsive workbench, a research project headed by computer science professor Pat Hanrahan, and then Gates allowed Levoy's team to make a quick scan of his head.

They produced a 3-D computer image that later was displayed on video monitors when Gates was introduced at the start of a special seminar called ``The Future of Computer Science Technology.''


More information, photos and a video demonstration of the 3-D faxing project are available on the Computer Graphics Laboratory World Wide Web page at . Click on Cool Demos, then Happy Buddha.