AuroraRT

# AuroraRT Shaderpack ## Short Summary **AuroraRT** is a premium, next-generation visual overhaul for Minecraft, built to deliver a distinct, atmospheric polar aesthetic and cinematic rendering quality. Modified from Complementary Shaders under the terms of the Complementary License Agreement 1.6, AuroraRT replaces standard environments with a curated visual identity featuring analytical sky scattering, dynamic aurora borealis, view-space raymarched reflections with advanced temporal denoising, physically based depth-of-field, and a fully calibrated ACES filmic color pipeline. Designed for Minecraft 1.21+ running Iris and Sodium, AuroraRT blends visual grandeur with robust performance profiles. --- ## Detailed Description ### Polar & Cosmic Skies AuroraRT features a bespoke atmospheric system that shifts away from default color maps to establish a majestic, cool-toned environment: - **Analytical Rayleigh & Mie Scattering**: A procedural sky dome calculating Rayleigh molecular scattering alongside a Henyey-Greenstein Mie phase function $P_{HG}$ for realistic solar halos that respond dynamically to atmospheric moisture. - **Ozone Twilight Sky Layers (Chappuis Absorption)**: Simulates sunlight absorption through the upper ozone layer using a wavelength-specific extinction coefficient. During sunsets and sunrises, this creates a beautiful pink-to-rose twilight arch fading into a deep teal zenith. - **Dynamic Aurora Borealis**: Multi-colored auroral curtains (flowing from neon green and teal to cosmic magenta) project vertically into the night sky, animated with a stable curl noise warp and a slow, majestic drift. - **Cosmic Parallax Nebulae & Twinkling Stars**: Procedural, multi-layer gaseous nebulae drift across independent parallax matrices. Stars are rendered as crisp, circular pinpricks of light rather than square blocks, twinkling with independent three-channel color offsets. ### Volumetric Atmospherics - **Exponential Height Fog**: Implements an analytical integral of exponential density over the view ray. Fog gathers realistically in low-lying valleys and thins out naturally as you ascend, shifting colors dynamically across biomes (such as a dusty gold in deserts, grey-blue in the Pale Garden, and cyan-white on snowy peaks). Fog density scales down on clear nights to open up the stars. - **Beer-Powder Volumetric Clouds**: Fluffy, self-shadowing volumetric clouds calculated using a Beer-Powder multiple-scattering model. This creates highly detailed cloud volumes with bright silver linings around the sun or moon, free of high-frequency coordinates warping. - **Nether Biome Storms**: Volumetric dust and fog colors transition dynamically based on your coordinates in the Nether (deep crimson in Crimson Forests, turquoise-teal in Warped Forests, ghostly blue-cyan in Soul Sand Valleys, and ashy purple-grey in Basalt Deltas). - **End Black Hole & Accretion Disk**: Renders a gravitational lensing effect around the sun/moon vector in the End dimension, distorting surrounding ender stars and cosmic nebulae around a rotating accretion disk and photon ring. ### Materials & Physics - **Next-Generation Water Shader**: A fully analytic procedural surface — five large directional wavetrains (wavelengths of roughly 4 to 19 blocks) summed into a rolling swell, with the surface normal taken directly from the analytic height gradient. Because there is no high-frequency normal-texture detail, the surface stays smooth at every scale and is free of the sub-pixel specular shimmer/grain that plagues texture-sampled water; additional distance- and grazing-angle flattening resolves far water into a clean mirror. Deep water uses spectral Beer-Lambert absorption to fade from pale teal shorelines into rich indigo depths, adds volumetric in-scattering so the water column reads as a lit medium rather than a darkening filter, and uses a physically based Schlick fresnel (water IOR 1.33). Surfaces feature sun specular glints derived from the wave gradient, backlit wave-crest subsurface scattering, and dynamic foam on both shorelines and wave crests. The underwater environment adds physically modeled single-scattering volumetric light shafts that dynamically match biome-specific water colors, animated seafloor caustics, a seamless horizon transition (eliminating artificial vertical borders), real-time transmission of the sun, moon, and sky dome through the water surface based on depth, and depth-limited volumetric god rays with dynamic 3D current noise simulating floating organic particles. - **Snow, Sand & Ice Realism**: Snow blocks, sand blocks, and snowy world overlays implement a physically based subsurface scattering model (`subsurfaceMode = 4`) that softens normal shading contrast and adds a backlit glow. High-frequency procedural micro-crystal normal maps cover snow surfaces, embedded with twinkling sparkles that modulate slowly over a 23-bit integer bitmask hash. Ice and snow sparkles are softened and fade over distance to ens