"They explode too big for the number of particles." Exactly right, and the
mistake was treating star count and break size as two knobs. They are one.
A sphere is filled by rays per steradian, so doubling the radius needs FOUR
times the stars to read equally dense. The previous commit sized the break
honestly — 30-52 m, a real 6in shell — while leaving it at 64 stars, and 64
rays spread over 40 metres is not a flower, it is a handful of unrelated
dots drifting apart.
So: 2560 beads per shell at 8 per trail = 320 stars, up from 64, and the
break pulled in to 17-28 m (a 3in shell) from 30-52. Density is the product
of both changes — five times the rays into a third of the volume.
Beads are also slightly larger (1.25 from 0.9), because a bead 60+ metres
away has to survive being a couple of pixels.
Cost is 92k triangles at the 18-shell peak, which is the honest price of
density and exactly the sort of thing the thermometer exists to cut on a
headset. Still one instance per shell on the CPU.
A test pins SPARKS_PER_SHELL / TRAIL_LEN to the star count the shader
hardcodes. Drift there does not fail loudly — the Fibonacci distribution
just covers the wrong fraction of the sphere and the break stops being
round, which looks like a tuning problem and is not one.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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