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 ensure a smooth, noise-free appearance.
• Iridescent Translucents: Clear glass features fresnel opacity and subtle iridescence, while stained glass blocks exhibit high backlit saturation and iridescence.
• Nether Portal Vortex: Transformed with a noise-warped vortex spiral, 3D parallax sparkles, calibrated emission levels to prevent overexposure, and full block shadow voxelization.
• Integrated PBR (IntegratedPBR+): Enabled by default, offering auto-generated normal maps (bump-mapping) and coated textures (dust details) across default blocks without requiring external PBR resource packs.

Lighting & Path Tracing

• Software Path Tracing Engine: A physically rigorous, real-time software path tracer calculated dynamically over the voxelized landscape using cosine-weighted hemisphere sampling and ray-marched secondary bounce evaluation.
• Voxel Global Illumination (Voxel GI): Adds real-time diffuse indirect lighting (GI) and ambient occlusion (voxel AO) generated dynamically from the voxelized scene, calculating bounce transfer from glowing blocks and sky illumination onto surrounding surfaces.
• Jitter-Rotated Shadows with Uniform Vogel Disk Sampling: Shadow maps are sampled using a mat2 rotation matrix driven by Interleaved Gradient Noise. PCF samples are distributed via a uniform Vogel disk distribution (pow(r, 1.1)) to minimize subpixel temporal dither noise. It features slope-scaled and distance-scaled PCF filtering offsets to dynamically smooth out low-resolution shadow map pixels at grazing angles and in the distance, backed by a slope-scaled shadow bias to completely eliminate shadow acne without peter-panning.
• Warm Cozy Blocklight: Torch and blocklight emissions are shifted to a warm peach/golden amber, contrasting beautifully against cool night atmospheres.
• Volumetric Godrays: Volumetric light shafts are shaped using a forward-scattering Henyey-Greenstein phase function. At night, light shafts are dynamically colored by the aurora borealis, streaming green, teal, and magenta rays down onto the landscape.
• Advanced Color Tracing (ACT): Voxel-based floodfill lighting enables colored blocklight emissions (such as colored candle lighting) and light-leaking corrections in caves.

Reflections

• World-Space Player Reflections (WSR): Captures the player's vertex coordinates and UVs in the shadow pass, storing them in a layout-conformed SSBO (playerVerticesSSBO) and caching the player's skin into a dedicated atlas image (playerAtlas_img). This allows the ray-tracing pass to intersect and shade the player model dynamically in reflective surfaces (water, metals, ice).
• View-Space Raymarched Reflections (SSR): Employs perspective-correct 3D raymarching in view space with binary step refinement, preventing the geometric stretching and distortion artifacts typical of 2D screen-space raymarching.
• Ray Reconstruction (Denoising): Reprojects reflections temporally with an 86% history retention and strict depth/normal validation. Banding is smoothed out by an edge-preserving bilateral spatial filter that scales with the quadratic power of roughness, early-outing on perfect mirror surfaces to conserve GPU bandwidth.
• Roughness-Jittered Glossy Reflections: Perturbs reflection vectors inside a roughness-scaled cone using a spatio-temporal dither, resolving into glossy reflections on rough metals, wet blocks, and glazed terracotta.

Post-Processing & Camera

• ACES Filmic Tonemapping: Selectable alongside Lottes, Krzysztof Narkowicz's ACES curve fit provides a punchy, high-contrast cinematic film response. It is integrated with a dynamic contrast slider and targeted saturation/vibrance boosts to preserve color richness.
• Dreamy Ambient Bloom: Bloom weights are shifted towards large-scale blur tiles (LOD 4 to 8) while suppressing sharp highlights, wrapping torches, lava, and glowing ores in a soft, dreamy mist.
• Cinematic Depth of Field (DOF): Simulates physical lens optics in linear space. Foreground objects blur rapidly (macro focus) while background blur is capped to preserve scene context. Blur samples are distributed using a dither-rotated Fibonacci spiral (up to 64 samples) with settings for polygonal aperture blades (5 to 8 blades), anamorphic squeeze, cat's eye lens vignetting, specular highlight boosts, and depth-aware silhouette bleed prevention.
• Cinematic Photo Mode: A dedicated toggle that disables TAA subpixel jitter and history blending to completely eliminate ghosting and motion blur during high-resolution screenshot capture. It automatically hides block selection outlines, leashes, and debug lines, forcing max DOF quality (64 samples) and silhouette bleed prevention.

---

Performance & Customization Profiles

AuroraRT provides 9 pre-configured quality profiles tailored for different hardware setups, allowing players to scale rendering features from maximum performance to fully path-traced realism.

The 9 Profiles at a Glance

1. Potato: Maximum performance optimization. Disables shadows, voxel blocklighting, and block reflections while maintaining the core polar/cosmic color palette.
2. Very Low: Introduces low-resolution real-time shadows at a 4-chunk rendering distance, with basic water reflections.
3. Low: Scales real-time shadows to a 6-chunk distance, upgrades water reflections to screenspace raymarching (Medium), and enables basic block specular highlights.
4. Medium: Extends shadow distance to 8 chunks, enables Fast Approximate Anti-Aliasing (FXAA), and introduces low-quality volumetric light shafts.
5. High (Default): The standard intended experience. Features medium shadow quality over 10 chunks, high-quality PBR block reflections, 8-chunk voxel blocklight (Advanced Color Tracing), volumetric clouds, and entity shadows.
6. Very High: Upgrades shadow distance to 12 chunks, switches detail/cloud quality to High, enables 8x anisotropic texture filtering, and retains 8-chunk voxel blocklight.
7. Ultra: The highest standard preset. Delivers high-quality shadows over 16 chunks, 16-chunk voxel blocklight, 8x anisotropic filtering, and enables full World-Space Reflections (WSR).
8. Cinematic: The ultimate visual experience, designed for high-end GPUs or high-resolution screenshot captures. Maxes out shadow distance to a massive 32 chunks, voxel blocklight to 32 chunks, anisotropic filtering to 16x, shadow casting to Full block-entities, and elevates SSAO to High.
9. Path Traced: Enables the full real-time software path tracer (cosine-weighted hemisphere sampling with secondary bounces) on top of Voxel GI/AO, 16-chunk colored voxel blocklight, hybrid World-Space + Screen-Space Reflections (WSR+SSR), and world-space player reflections. Shadows and detail match Ultra (high-quality shadows over 16 chunks, 16x anisotropic filtering). Aimed at high-end GPUs and screenshot capture.

Configuration Reference Matrix

Feature	Potato	Very Low	Low	Medium	High (Default)	Very High	Ultra	Cinematic	Path Traced
Real-Time Shadows	OFF	Very Low	Very Low	Low	Medium	Medium	High	High	High
Shadow Distance	2 Chunks	4 Chunks	6 Chunks	8 Chunks	10 Chunks	12 Chunks	16 Chunks	32 Chunks	16 Chunks
Water Reflections	Potato	Low	Medium	Medium	Medium	Medium	Medium	Medium	Medium
Block Reflections	OFF	OFF	Low	Low	High	High	High	High	High
Volumetric Light Shafts	OFF	OFF	OFF	Low	Medium	Medium	High	Very High	High
SSAO Quality	Medium	Medium	Medium	Medium	Medium	Medium	Medium	High	Medium
Temporal AA (TAA)	ON	ON	ON	ON	ON	ON	ON	ON	ON
Anti-Aliasing (FXAA)	OFF	OFF	OFF	ON	ON	ON	ON	ON	ON
Detail Quality	Potato	Potato	Medium	Medium	Medium	High	High	High	High
Cloud Quality	Low	Low	Medium	Medium	Medium	High	High	High	High
Texture Filtering (AF)	OFF	OFF	OFF	4x	8x	8x	16x	16x	16x
Advanced Color Tracing	OFF	OFF	OFF	4 Chunks	8 Chunks	8 Chunks	16 Chunks	32 Chunks	16 Chunks
Voxel GI / AO	OFF	OFF	OFF	OFF	OFF	OFF	ON	ON	ON
World-Space Reflections	OFF	OFF	OFF	OFF	OFF	OFF	ON	ON	ON
Software Path Tracing	OFF	OFF	OFF	OFF	OFF	OFF	OFF	OFF	ON
Entity Shadows	OFF	OFF	OFF	OFF	Regular	Regular	Regular	Full	Regular

Custom AuroraRT Settings Screen

The shader options menu is completely reorganized and custom-labeled in the Iris configuration GUI to provide a bespoke user experience:

• §ePerformance Tuning§r: Manage pre-configured presets (Potato to Ultra) and toggle specific performance-scaling options.
• §bCinematic & Camera§r: Configure ACES Filmic vs. Lottes tone curves, dynamic bloom, TAA filters, and physical Depth of Field options.
• §dShadows & Ambient Lighting§r: Tweak PCF filter offsets, slope-scaled biases, warm amber blocklight, and ambient light cycles.
• §cAurora Skies & Atmospherics§r: Tweak dynamic auroral curtains, star scintillation, cosmic nebulae, height fog, and storm limits.
• §aPBR & Surface Materials§r: Configure Integrated PBR+ bump-mapping, procedural water waves, and sparkling snow/ice crystals.
• §7Extra Features§r: Toggle block outline styles, moon phase lighting influences, hand swaying, and debug variables.

---

Technical Compatibility & Exclusions

Supported Specifications

• Minecraft Version: 1.21+ (and compatible newer versions).
• Required Mod Loaders: Iris Shaders and Sodium (Fabric/Quilt).
• Hardware: Compatible with modern NVIDIA GeForce, AMD Radeon, and Intel Arc GPUs.

Verified Exclusions & Unsupported Features

To ensure complete transparency and prevent configuration issues, the following systems are explicitly unsupported or excluded:

• Hardware-Accelerated Ray Tracing (Vulkanite / Dirt RT): AuroraRT is an OpenGL-based shaderpack and does not support hardware-accelerated Vulkan path-tracing pipelines.
• Vanilla Core Shaders (VPT-1.3.0): Vanilla core shaders are disabled by Iris when a shaderpack is active, making VPT integrations incompatible.
• VTXS Screen-Space Traversal: Hierarchical Hi-Z bitmask raymarching is not included due to copyright restrictions.
• Contact-Hardening PCSS Shadows: Temporarily disabled due to stepping artifacts under shadow map resolution limits.
• Screen-Space Lens Raindrops: Removed from post-processing to maintain high performance and clear viewports.
• Apple Silicon M-Series ACT: Advanced Color Tracing (voxel lighting) is disabled on Apple GPUs due to driver limitations regarding vertex shader image writes.
• OptiFine ACT / Reflection Resolution: Voxel colored lighting is disabled on OptiFine due to lack of image/SSBO support. Dynamic reflection resolution requires Iris 1.7+ and will display an error message on OptiFine.

---

Legal Credits

AuroraRT is distributed as a Modified Pack under Section 1.3 of the Complementary License Agreement 1.6 (included as License.txt within the shader pack).

• Original Pack: Complementary Shaders by Complementary Development.
• Official Complementary Site: https://www.complementary.dev