Zenith, moving

An orthographic zenithal projection. Height above the horizon is measured from one overhead point that sits off centre, and equal steps of altitude become radial bands that compress toward the rim. Each band is ruled at a density that is a function of its altitude alone, tangentially or radially by turns and crossed in both directions where one cannot carry the tone, so the ground itself is the measurement rather than a thing the measurement is drawn on top of. Beyond the rim there is no altitude, and that region is solid black.

The still version of this was made in September 2026 and stops there. Moving, the azimuth turns by one sector every two bars, the scatter of solid cells is redrawn each bar, and the wedge printed with the inks exchanged jumps to the next sector on every beat of the bar. The projection is the same projection; what the beat does is move the observer around under it.

The piece is handed the time and the beat rather than reading a clock, so any frame can be drawn on demand and the same inputs always draw the same picture. This is a reimplementation of the published still under that contract, not the original program with time added to it.