Watchout version 4.x can only output from one Display PC to one
projector per licence, so a 3-screen show would need 3 Display PCs each hooked to one
projector each and 3 licences (4 licences if you are also using a Production PC to control the 3). With a dual output graphics card, you can set each Display PC to clone the output such that one output is to a
projector and the other is cloned to a
desk monitor without the need for an additional licence.
Watchout version 5.x changed the requirement, and is able to output to a maximum of 6 outputs from one Display PC with one licence, assuming the PC has the muscle and capabilities especially Active display port adapters and
EDID managers. All outputs from the one PC must be of the same resolution. The other requirement is that
Watchout (all versions) can only communicate with one graphics card in the Display PC. Other graphics cards installed will merely display the fullscreen
Watchout logo and nothing else.
So if you have WO v4.x, sorry, you are restricted to one
screen from one Display PC per licence.
A possible option, and I emphasize, possible, is to have a Matrox Triplehead2Go between the output of the Display PC and the 3 projectors, again assuming the Display PC has the muscle to output without playback problems a very wide high resolution
image that will be split by the Matrox. I don't have a Matrox, so can't try.
Lately, another possible option has appeared using a display port
hub (or mini-display port
hub) such as the EVGA MST where you can connect a single display port output from the graphics card to 2 or more displays/projectors. (Avoid the Club3D MST - reported unreliable).
Your most reliable option is to upgrade WO version 4 to version 5 at least 2 of your licences (needs an exchange of dongles) - one for the Production PC and one for the Display PC, and buy 2 or 3 Active Display port adapters (the
DVI output of the graphics card does not need such an
adapter). Make sure it is ACTIVE.
Passive ones will not work. Chances are you will also need an
EDID Manager for each output when you exceed 2 outputs from a graphics card, especially with long cable runs to the projectors (eg. Gefen
DVI Detective - about one of the cheapest available). 1-3m cables to monitors/projectors may work fine without the
EDID Manager for 3 outputs, but this is where one gets tricked into thinking it will also work when on-site with the projectors.
good luck!
ThomasL