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Build Your Own: Wall-Sized 3D Gaming, Just Like Theaters Do It

Installation And Set Up

This section will be of interest mostly for folks who are planning to recreate a dual-projector, polarized 3D theater in the home. Casual readers might be best served by forwarding to the next page.

So you want to set up your own dual-projector theater, huh? The first thing to do is to install the screen. To do that, you'll want to test-fire your projector and see how far away from the screen it will have to sit to produce the size of the image you'd like. At this point, you should have a good idea of where everything will be placed.

Our particular screen is made of a special silver fabric that preserves the polarization of light and it requires a lot of elastic mounting strips for installation. It takes some time, but the process isn't rocket science. To properly mount the screen, a frame is ideal, but for the purposes of our testing, we'll apply it directly to the wall.

Setting up a dual-projection system is, well, twice the work of setting up a single projector. But the work to install the projector mounts is not simply doubled. Care must be taken to place the mounts so that the projector lenses will be aligned as close as possible. For a dual-projector system to work properly, the displays must overlap perfectly and this is difficult to do if the projectors are mounted too far away from each other. Of course, the projectors do need a bit of breathing room, and it is important that airflow must be allowed to reach the hardware so that the cooling fans can do their job.

As with any projection system, power and display cables need to be routed to each unit. In our somewhat temporary setup, we'll simply mount the cables to the ceiling, but a permanent solution would probably benefit from a stealthy installation behind the wallboard or ceiling tile.

With the projectors mounted and cables attached to the PC, it's time to set up an extended desktop with both projectors as active side-by-side monitors. Using a plain-white desktop background here will help keep the visual confusion to a minimum. Both sides of the desktop are projected onto the same screen space, so the bright light from both displays will wash out the detail. In the Radeon or GeForce drivers, assign the primary desktop to the left display on the extended desktop for now--we might have to switch this later, but this is a good starting point.

At this point, install the TriDef and iZ3D drivers. After the install, select dual projection as the output option for each. There are more details about the driver setup on the following page.

Notice the edges - the projectors haven't yet been aligned

Now is the time to do a preliminary screen alignment. Make sure both projectors are outputting the same size of image to the same space. Once again, using a plain white Windows background will come in handy, as it makes it easier to see when one display is bleeding over the edge of the other. It'll take a bit of tweaking to adjust the zoom, focus, and keystone settings to bring the displays acceptably close, but it isn’t as difficult as we imagined it might be. Truth be told, when your eyes see the separate images through the glasses, your brain compensates for a lot of imperfections in alignment.

With the preliminary alignment done, the edges line up much closer

After the preliminary alignment, install the polarized filters. This requires a bit of care because each projector will use the same kind of filter, but the axis of polarization will be rotated by 90 degrees in relation to each other. Also remember that the polarized filters only work in one direction. You can test the filter orientation by looking at the screen and wearing a pair of 3D glasses. Now look at the display and adjust the filter until only one eye can see its projector's output. This is usually easy because, in an extended desktop configuration, one projector probably displays the Windows icons and the other is probably blank. It's not important which eye is linked to which projector at this point, as long as one eye receives only the light from one projector.

Notice the right filter blocks the desktop icons intended for the left eye

When installing the polarized filters, it is also important to keep in mind that if it isn't perfectly aligned to the plane of the glasses, the viewer might experience unpleasant crosstalk effects. Also remember to install the filter as far as possible from the projector while keeping all of the light output within its boundaries. Heat from the powerful bulb can quickly damage the expensive filter if it is placed too close. The farther the filter is from the lens, the more area it has to absorb the heat. Ideally, the light output from the projector will cover the polarized filter all the way to its edges.

In-game, we can see both perspectives with the glasses off

Through the polarized glasses, only one perspective can be seen for each eye

After the polarized filter is installed, it's time to test the system. Launch a game in 3D mode and pay attention. If the 3D effect appears disorienting and confusing, the displays probably need to be switched as the image intended for the right eye is being displayed in the left eye and vice-versa. This is done in the graphics card's display driver panel. Simply swap the location of the displays in relation to each other when configuring the extended desktop and try again.

This is the kind of in-game screen that is ideal for final calibration

By now, the display should be working in-game and you will probably be completely amazed by the result, but there's one more thing to do: find a static screen without a lot of 3D effect in the Options menu and remove the 3D glasses. This is a good reference to use for a final alignment of the projectors. A 2D Options menu provides a lot of identical detail on each screen and the text should make it obvious that things are in or out of alignment. Align the projectors until the image looks as clear as possible with no blurry edges.

That's all that's involved with the installation and frankly it sounds more difficult than it actually is. If you're intrepid enough to get this far, you're probably surprised at how quickly the system is up and running once the projectors are mounted. I expected some additional driver hocus-pocus to deal with, but our test system was up-and-running fairly quickly.