Models a stage and a lighting rig and works out the illuminance on the deck before anyone gets to the venue. Build the rig from truss, bars and stands, focus each fixture at a point on the stage and let it work out the pan and tilt, then read the levels off a heatmap with the beam cones drawn over it.
The bit worth having is one toggle between a horizontal plane and a vertical one. A rig can be perfectly even on the floor and still flat and shadowless on faces, because overhead light arrives nearly edge-on to a vertical surface, and flipping between the two turns the ranking of your fixtures upside down. Every fixture carries a badge saying whether its numbers were measured from an imported IES or EULUMDAT file, transcribed from a named datasheet, or synthesised from an archetype, so you always know which lux figures rest on a guess.
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