crypt_sky_mat

# crypt_sky The Spooky Spook Spook night sky, a `@domain: sky` shader. It writes only `fragment(in: SkyInput)`. Everything in it is procedural and animated on `in.time`: - **Gradient:** a deep violet-black zenith fades to a violet horizon (`zenith_color`, `horizon_color`, `ground_color`). - **Horizon glow:** a candle-amber band hugs the skyline and a sickly ecto-green band sits just above it. Both wander in azimuth and breathe over time (`glow_amber`, `glow_green`, `glow_intensity`). - **Stars:** two layers of twinkling stars from a 3D cell hash, so there is no seam and no pinch at the pole (`stars_intensity`). - **Moon:** a large moon toward `moon_dir` (xyz, toward the moon). It has fbm maria, two sizes of crater with bowls and rims, limb darkening, a slow ectoplasmic shimmer, a cold halo and a faint shimmering green ring at about 2.4 radii. Controls: `moon_size` (angular radius in radians), `moon_brightness`, `halo_intensity`, `ring_intensity`. - **Aurora:** domain-warped ectoplasm ribbons plus a violet veil, projected onto a high virtual ceiling so they converge toward the horizon (`aurora_intensity`). - **Mist:** ghostly bands crawling along the horizon (`mist_intensity`). - **Lightning:** a sheet flash toward `flash_dir` plus a jagged bolt shaped by `flash_seed`, scaled by `lightning`. It is 0 at rest, and `CryptSky` pulses it at runtime. `time_scale` speeds up or slows down every animation, and `exposure` scales the output. The output is linear radiance, and the sky domain's display transform tone-maps it. `game.sky.crypt_sky_mat` is the material over this shader. The `CryptSky` component points a `Skybox` at it. The engine's volumetric cloud layer composites over this sky, so the moon and stars show only through gaps in the clouds.