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Is your 21" monitor with 0.22mm dot pitch just not giving you the picture you need? Maybe you need the 3-D resolution that StereoGraphics' CrystalEyes stereo eyewear offers. In addition to the stereo goggles that come in the CrystalEyes package, the product requires a PC emitter, cabling, a video card, and software that supports stereo imaging.

Hardware Setup Is Easy
Finding hardware support for CrystalEyes isn't difficult. Many OpenGL video cards from manufacturers such as Intergraph, HP, Creative Labs, Diamond Multimedia Systems, and Dynamic Pictures have integrated support for stereo imaging.

You connect the PC emitter to the video card's stereo port. You can identify a card's stereo port by the imprint of a pair of glasses or the word stereo; the stereo port usually resides alongside the trapezoidal 9-pin video port. Stereo ports come in numerous designs: 3-pin DIN connectors, 7-pin DIN connectors, or single-pin male connectors, depending on which company's video card you have. You need to be sure your emitter comes with a cable that matches the connector for your video card.

The lightweight CrystalEyes goggles fit nicely over most pairs of glasses. The goggles' two lenses are LCD screens with shutters that rapidly open and close. CrystalEyes requires stereo software, which produces offset images for the right and left eyes. To produce the 3-D effect, the lenses' shutters alternate opening and closing in sync with the stereo video display, so that each eye sees only the image designed for it. The PC emitter broadcasts an infrared signal to the glasses that coordinates the onscreen images with the shutters.

When you look at a stereo image without stereo eyewear, you see a ghosted image. When you look through stereo eyewear without a stereo image on the screen, the display appears to flash. The juxtaposition of the opening and closing of the goggles' shutters and the monitor's refresh rate creates the flashing effect.

To best display stereo images, your monitor and graphics card need to support a refresh rate of 120Hz. StereoGraphics makes an emitter that works with monitors or graphics cards that can't support 120Hz refresh rates, but the 3-D effect isn't as good.

Finding Software Is Difficult
Windows NT applications that take advantage of CrystalEyes' 3-D capabilities are scarce. To test CrystalEyes, I installed ERDAS's IMAGINE 8.3 geographical imaging software on an Intergraph TDZ 2000 with dual 333MHz Pentium II processors and a RealiZm II VX113 GT 3-D graphics card.

IMAGINE uses a process called stereoscopy to produce stereo images from high-resolution satellite images. Stereoscopy uses stereo-pairs, two images of the same area taken from different angles, to determine the lay of the land. The resulting composite image is known as a Digital Elevation Model (DEM). IMAGINE's images have a resolution of one pixel to 20 meters. I expect 3-D products' resolution to improve soon, because new satellites will offer a resolution of 1 pixel to 1 meter.

I used CrystalEyes to view a DEM of Palm Springs, California, and the San Bernardino National Forest. Looking at IMAGINE's stereoscopic images through the CrystalEyes goggles is similar to the view I imagine flight simulators provide. The digital image comprises several layers of textures and vector images, including the topography of the terrain and the buildings and streets of Palm Springs. The 3-D effect isn't exactly depth defining, but it gives you a better sense of the texture and layout of the land than you have in 2-D.

The military has traditionally used stereoscopy in classified operations, but the technology is quickly moving into the mainstream as image resolution and PCs' processing power increase. Today, many government and private organizations use satellite-imaging technology to determine the quantity and quality of natural resources, research the health of crops, and perform habitat and environmental impact analyses. Other fields in which 3-D vision is gaining ground are biotechnology, molecular modeling, CAD, computer-aided manufacturing (CAM), and ergonomic design.

Despite the currently limited number of stereoscopic NT applications, I expect to see more 3-D applications for NT. Companies continue to port their UNIX products to NT and NT workstations continue to make inroads into 3-D imaging, which was once the exclusive domain of UNIX workstations. For a list of software that is compatible with the CrystalEyes goggles, download the CrystalEyes Software Catalog from StereoGraphics' Web site (http://www.stereographics.com).

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