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is the only one (in that example) that has light materials applied as channels to its
Mesh – one for rendering each gobo pattern respectively. Each light material refers to
its own gobo texture (in this case they are both the same) and has individual color
information. In addition, each light material has the TexGen-with-referential effect
applied, where each material refers to its own projector. To be more precise, each
projector model is composed of light model as a parent (not active, just acts as a
holder) and a 3D Frame set as a child, which acts as the actual reference for the
respective light material. Note that, as the TexGen settings are chosen to be Planar,
the eventual reflection output does not depend on the distance between the projector
and the building – instead, it only depends on the size of the face of the bounding box
of the reference object! In that sense, it is not a totally accurate representation of
projector light reflections. This is true in yet another regard – the faces of the lit object
do not “know” if they are in a shadowed area, so they render the reflection anyways.
Figure 64. Illustration f wrongly lit faces; influence cones deliberately left to indicate that Planar reflection depends
only on the size of the cube which acts as referential object
So, although this is not an ideal simulation of projector gobo pattern
reflections, it still solves a lot of problems – how to composite images from several
projectors, primarily. In addition, the default behaviour of this effect is such that
rotation of the referential object is effectuated as rotation of the reflected pattern – in
that sense, it is a great relief to the cue engine, as effectuating the cue rotation value
for a given projector at a given time means only setting the corresponding rotation for
the projector referential object; this operation is relatively trivial and economical in
the context of Virtools scripting language (compared to drawing a texture “manually”
from the same VSL scope, which is impossible to conduct in real-time – hence
"DMX Director" - Architecture of a 3D light-programming application, in a multi-user Internet environment
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