Issue: Volume: 25 Issue: 2 (Feb 2002)


By Joe Greco

Software designers are always developing new rendering algorithms to make 3D models look more realistic. However, these models, be they the latest designs for a cell phone or animated creatures for a new movie, eventually end up on flat 2D screens.

So that 3D models can also be viewed in 3D, some companies have created products based on stereoscopic technology that incorporates 3D glasses. In conjunction with the proper software, a user wearing the glasses can view 3D models that appear to project from or hover in front of a display.

While this technology has become cheaper at the same time that it has improved, many users don't like to don goggle-like eyewear when designing. So, to take stereo viewing to the next level, other companies are creating products that enable 3D viewing without glasses or other special gear. I recently tested one of these glasses-free displays, a 15-inch flat-panel LCD called the 2015XLS from Dimension Technologies Inc. (DTI) based in Rochester, New York.
The 18-inch version of DTI's 3D flat-panel display costs $6999.

Setting up the monitor was like setting up a regular flat-panel display except for an additional cable that gets connected to the computer's serial port. This cable has to do with the various 3D modes that the monitor can output.

The monitor comes with a demo application called TextureEyes that allows users to view sample 3D models as well as bitmapped images. There is also a program called dtint32i that helps the user set up bitmapped images in order to create a 3D photograph. As opposed to the "popping out" effect you see when looking though 3D glasses, the images on the DTI monitor generally seemed to be receding into the screen, which was equally effective.

Besides not requiring glasses, another advantage of DTI's technology is that three people can sit comfortably next to each other at arm's length from the screen and still observe the 3D effect. This is because the monitor uses a lenticular screen to help create the stereoscopic effect, and as a result three "viewing areas" are created. The monitor has a red indicator light on the front, and when it appears to be off, this means you are in an ideal zone. However, even when this light was "off," I noticed that, with certain models, distortion was still visible. This occurred mainly near the edges of the screen, although it was less noticeable in the TextureEyes program than it was with images created in off-the-shelf software.

Once I was familiar with the monitor's capabilities, I wanted to view models created in standard CAD and other 3D programs. However, just because you have a 3D monitor, or any stereoscopic device for that matter, doesn't mean it is plug and play, as several hardware and software requirements must be meet.

The first of these is a graphics card with stereo capabilities. I was using an Nvidia Quadro, which met this requirement, but some tweaking was needed to achieve the 3D effect. First, I turned on an OpenGL option that told the card to enable its capability to read the quadbuffered stereo algorithms generated by any CAD/3D software on a computer that has this ability. Quadbuffered stereo is a routine within OpenGL that can be employed by 3D applications in order to show stereo images. With the stereo capability activated, it has to be turned on in the individual 3D application. Depending on the program, this is done in different ways. For CAD applications such as SolidWorks and Solid Edge, I did what users using the StereoGraphics' glasses technology (for example) would normally do-I downloaded a plug-in from the StereoGraphics Web site. When loaded into SolidWorks, two new choices appeared in the View menu called Stereoscopic Viewing and Stereoscopic Options. Selecting the former makes the model on the screen look like is in the middle of an earthquake, as it shakes violently from side to side.

At this point, it is time to put the DTI monitor into 3D mode by pressing the Menu button on its front panel and then using the other buttons to set the Computer 3D Format to Frame Sequential Mode. This makes that flat jittery image appear amazingly three-dimensional. I then used the Stereoscopic Options command in SolidWorks to tweak the 3D effect a bit more.
Depending on the software you use, the DTI's stereo viewing capability can be accessed different ways, including as a plug-in within CAD programs.

I also downloaded the plug-in for Solid Edge, which appears as a single tool in its own toolbar, with no user options available. Here there seemed to be a bit more ghosting, and the best effect was actually when the red light was showing, as I positioned myself a shade off to the right and a bit farther back.

Some programs use methods other than generating frame sequential images to create a stereo pair, including field sequential, side by side, and top and bottom. The DTI monitor can be set to run in any of these modes and then switched back to a regular 2D screen with the touch of a button, ideal if you are using a 3D program with Photoshop, Premiere, or any non-3D program. In 2D mode, the screen is a little fuzzy, and normal white areas are off-white. On my particular display, the top right portion of the screen was a little dark, but it was not a real problem. If you don't want to switch back and forth, it is possible to work in either frame or field sequential mode, but the images will be even darker and fuzzier.

For users of software whose developers have decided not to access the OpenGL Stereo 3D routines, there is a solution. Nvidia Stereo 3D is a special driver that requires almost no work on the part of the developer other than following a set of Nvidia's guidelines. The limitations are that it only works with full screen applications such as games and the 3D effect is not as dramatic. However, considering that most games are based on DirectX, which does not have stereo support, this is a good solution.

If you cannot get your 3D software to generate a stereo pair, the other option is to use TextureEyes. The only problem is that this software doesn't read in common 3D formats such as IGES-it only reads the DirectX format. The answer is to use a program from Okino Computer Graphics called NuGraf, available for a free trial period at This software reads in many 3D formats and creates a file in the DirectX format for viewing in TextureEyes. I found that while this procedure was a few extra steps, the results were just as impressive.

At only $1699, this monitor is worth considering for anyone who would like to view 3D images the way they were meant to be seen, without glasses. DTI also has an 18-inch model for $6999.

Just as we went to press, I had the chance to work briefly with the Syn tha Gram, an autostereoscopic monitor from 3D-eyewear developer Stereo Graphics. Compared to DTI's system, it had a brighter image but it isn't recommended for 2D work, and I felt the 3D effect was a little less dramatic.

Although viewing 3D images in 3D is very cool, I did try to consider whether it was a productivity enhancer. I decided that the technology does help creativity by improving visualization, but I wouldn't say that it made me more productive or efficient. These aspects might be better judged over the long haul, however.

In any case, look for autostereoscopic technology to continue to improve, and in the meantime push your CAD developer to support 3D stereo viewing.

Joe Greco specializes in writing about computer-aided design. He can be reached at

Price: $1699
Dimension Technologies Inc. (DTI)