function rayBrightness
universe/src/craters.ts:958
How bright a ray system leaves the ground at a direction, 0 to 1.
Two terms with different reach. The continuous ejecta is the bright halo inside about 2.6 crater radii — the same deposit the height field raises as an apron, seen as fresh rock over mature regolith. The rays are thin filaments running out to sixteen radii, and they are what makes a young crater read as young from a hundred thousand kilometers away.
Both fade with the crater's own age. Nothing about brightness survives space
weathering: a lunar ray system is gone in about a billion years while the
bowl it came from is still there, which is why age drives this far harder
than it drives the profile in craterProfile.
- cratersreadonly RayCrater[]
- Undocumented
- grammarSurfaceGrammar
- Undocumented
- directionVec3
- Undocumented
Returnsnumber