AuroraFX Ultimate - technical notes

1. Shadowing
   shadowtex0 = all casters
   shadowtex1 = opaque casters
   shadowcolor0 = transparent caster color + alpha
   CINEMATIC averages a 5x5 kernel with Gaussian-like weights.

2. Terrain
   Dedicated gbuffers_terrain_solid is included for Iris 1.6+.
   Every use of WAVING_STRENGTH has a fallback definition in common.glsl.

3. Atmosphere
   Radial light shafts use Iris' shadowLightPosition/sunPosition view-space
   coordinates and sample the rendered scene along the light direction.

4. Water
   Layered procedural normals, Fresnel, sun specular, caustics and screen-space
   reflection approximation are combined. The highest profile increases sample
   counts and wave complexity.

5. Post
   Bloom is thresholded and deliberately kept low to avoid the washed-out
   white image that the earlier prototype produced. ACES-like tonemapping and
   restrained vignette preserve Minecraft's colors.
