ModernShaders - Iris / OptiFine shader pack (Overworld-focused)

INSTALL
1. Put this .zip (do not unzip it) into  .minecraft/shaderpacks/
2. In game: Options > Video Settings > Shaders, pick ModernShaders.
   Iris (recommended) or OptiFine, Minecraft 1.16+.

FEATURES
- Warped shadow map with soft PCF shadows
- Screen-space godrays occluded by terrain and leaves
- Animated water: waves, depth-based transparency, refraction, Fresnel
- Screen-space reflections on water and rain-wet ground, GGX specular fallback
- Warm coloured torch light, emissive glowstone/lanterns/lava
- Day/night/sunset colour transitions, atmospheric fog, ACES tone mapping

TUNING
Shader Options > Profile (LOW / MEDIUM / HIGH), or adjust the sliders directly.
If FPS is low: PCF_SAMPLES 4-8, SSR_STEPS 12, GODRAY_SAMPLES 12, shadow distance lower.

KNOWN LIMITS
- Not tested in-game by the author. If the pack fails to compile, the in-game
  shader log (Iris: logs/latest.log) names the file and line.
- Nether and End use the Overworld sky/sun logic, so they will look off.
- Glass and ice are approximated (lit using the surface behind them).
