Due to limited monitor size, the view that is available on a normal computer is a poor substitute for the wraparound windows of general aviation aircraft. This is especially true when the simulated aircraft has an open cockpit and an unrestricted view in almost all directions.
FlightGear can make use of multiple monitors to provide a nicer external view, possibly even wrap around, without special cabling. The additional computers and monitors need not be dedicated to this purpose. Once the command lines and fields of view (relative to the pilot) for each of the additional computers have been established, the main computer will make the necessary data available irrespective of whether those other computers are actually running FlightGear. In consequence, each of the additional computers can change from a `cockpit window' to a office software workstation (for someone else) and, when available again, rejoin the FlightGear simulation session.
FlightGear has built in support for network socket communication and the display synchronizing is built on top of this support. FlightGear also supports a null or do-nothing flight model which expects the flight model parameters to be updated somewhere else in the code. Combining these two features allows you to synchronize displays.
Here is how Curt Olson set up the example in figure 2:
There is no built in limit to the number of slaves you may have. It wouldn't be too hard to implement a full wrap around display using 6 computers and 6 projectors, each covering field of view on a cylindrical projection screen. Ideally, the master computer should be chosen to be whichever visual channel has the lightest graphical workload. This might be the dedicated instrument panel, for example. If the master computer has a heavy graphical workload, the other channels will usually lag one frame behind. Select the graphics realism parameters to ensure that all the visual channels consistently achieve a solid and consistent frame rate ( for example) and, if your video card supports it, lock the buffer swaps to the vertical refresh signal.
For optimal results, make sure the FOV each display subtends, matches the actual FOV that display covers from the pilot's perspective. From the top view, draw a line from the pilot's eye to each edge of the display. Measure the angle and use that for your visual channel configuration. Draw a line from the eye to the center of the display. Measure the angle from that line to the dead center straight ahead line. Use that angle for the view offset. This ensures that all objects in your simulator will be exactly life size.