Theatre Design & Technology - Winter 1996 - 41

mounted atop a 12-foot tall platform. The platform was masked on its
downstage side and remained open beneatll, prO\iding tlle main actor's
entraIlces to the stage. The follO\\' spots prO\ided a major source of illumination during tlle production. StaIlding on either side of tlle acting
aI'ea, they were capable of lighting the actors \\itll little bounce onto the
projection screen.

three-dimensionality. One projector was assigned to light eye \ie\vs only,
and the other to left eye \iews. Each \vas then polarized \\ith the "direction of pohuization" in opposition to the other. These opposite polalizations were done in such a manner as to match the polarization of the
special glasses given to each audience member. Using the glasses, the
audience could then see the projection from each projector only \\ith
the appropriate eye and the 3-D illusion was formed.
In fact, the operating principle of LCD projection pads decrees that
CO TROL
they are always polarized. So, the task of correctly polaIizing them was
Bellind the projection screen could be found a be\\~ldeling array of
accomplished not by adding additional polarized filters. Instead, an opequipment (Figure 5). Early in tech rehearsals, one crew member
tic matelial known as a half-wave plate or retarder was used on one of
dubbed the baIlk of computers, mixers, projectors, and canleras "Misthe LCD pads to "turn" the polaI"ization 90 degrees, then being opposite
sion Control."
to its mate. Finally, because we were unable to move the projectors far
At the heart of the formation (Figure 4) were two DukaIle ovel'
enough from the RP screen, the image was enlarged to the desired dihead projectors, each equipped Witll a NView LCD projection pad. Two
mensions by adding plastic fresnel magnifiers a few inches above tlle
projectors were needed in order to project graphics witll an illusion of
LCD pads.
Because the material we were to project was to come from multiple sources, tlle LCD pads were connected to a pair of digital \~deo
mixers. Each of these Videonics MX-l mixers were capable of s"~tching
between four \~deo sources and offered a vast selection of fades and
\\ipes. The most inlpOI1ant feature of this mixer was its ability to superimpose one scene over tlle otller. Each mixer required its 0\\11 ~deo
monitor to set-up and pre\~ew scene chaIlges aIld special effects.
The essential graphics that were to be projected onto tlle RP
screen were the ~liual worlds. Each scene had its own computer modeled emironment tllat could be traversed in real-time in cOlTespondence Witll the actors' movements. These worlds were created aIld run
on a PowerMac 7100/AV \\itll special prototype software loaned by tlle
Virtus Corporation of CaI)', NC. Tllis sofuvaI"e is identical to ViJ1us
WalkTbrougb Pro but has the added feature of stereograpllic screen
display. This added feature, wllich will soon be available on commercial
---------------'---'-------.",
releases of Virtus sofuvare, renders light aIld
left eye stereo views in several formats including
side by side pictures.
Because the AV-equipped Mac is capable of
running two sepaI"ate monitors \\~th its two
\~deo Clli'ds, it was possible to enlarge the side
--------------~by side stereo pictures in such a maIlner that
each picture filled one of the monitors. Then tlle
two seperate monitor outputs were converted to
staIldaI"d \TSC \~deo signals aIld sent to tlle two
~deo mixers. The signal from tlle 1ac AV CaI"d
was convel1ed to \ideo internally, while the signal from tlle staIldaI"d ~deo card required all
external \~deo encoder, in tllis case a Focus LTV Portable Pro.
Figure 3 (above):
Asecond PowerMac computer was also
actors in "TV studio"
connected to the ~deo mixers ~a a ~deo enwith chroma-key
coder. This computer was used to generate titles
screen; Figure 5
at the top of the show, to create a few special
(top): "Mission
graphics used during segues aIld to run a comContro/"; Figure 6
puter generated version of The Head character
(right): control
in the graveyard of scene sLx. Tllis disembodied
equipment diagram.
head (Figure 13) has only three lines aIld

MISSIO

TD&T

WINTER

Table of Contents for the Digital Edition of Theatre Design & Technology - Winter 1996