The owner measured 63% GPU at night vs 28% by day: the starfield
lattice was the whole difference. Three lossless cuts:
- one packed-multiply hash round per cell instead of ~9 chained PCG
rounds (position/presence bit-sliced from one result, brightness/tint
from a second);
- the 3x3x3 neighbourhood sweep becomes the 2x2x2 block around the
sample — a star's visible footprint (a few px) is far smaller than a
lattice cell on screen, so any star outside that block is over a full
cell (>=15 px) away and contributes nothing;
- background mottle drops its invisible third octave.
Same densities, sizes, colours, and look; star positions reshuffle
(procedural layout, not authored). sky.frag.spv re-pinned.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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