Overview

Aurora-inspired color grading and sky replacement built on a minimal GLSL 1.20 pipeline.

This shader pack applies an aurora-themed visual treatment to the overworld and Nether through a small set of post-processing and material shaders. The main rendering work is performed in a composite pass that modifies sky rendering, applies scene-wide color grading, and adds simple animated color modulation. Additional shaders tint clouds and water using time-based aurora color cycles while keeping the player's hand unmodified.

Core Features

Procedural Aurora Sky

Visual Effect

The overworld sky is replaced with an animated aurora effect when rendering sky pixels. The aurora transitions between teal, blue, and purple hues and becomes more prominent at night.

Implementation

The composite pass identifies sky pixels using depth values (depth > 0.9999).

World-space view direction is reconstructed from:

gbufferProjectionInverse
gbufferModelViewInverse

Aurora bands are generated procedurally using:

sin(viewDir.x * 3.0 + t) * cos(viewDir.z * 2.0 + t * 0.7)

Color cycling is performed between three predefined aurora colors using a time-driven interpolation system based on frameTimeCounter.

Aurora visibility is weighted by:

view direction height (viewDir.y)
horizon blending
day/night state derived from sunAngle

Performance / Limitations

Single fullscreen composite pass.
Uses only basic trigonometric functions.
No volumetric rendering.
Aurora exists only as a screen-space sky effect.

Global Aurora Color Grading

Visual Effect

World geometry receives an aurora-tinted color filter.

The effect is lighter during daytime and stronger at night, shifting scene colors toward teal and cyan tones.

Implementation

For non-sky pixels, scene luminance is calculated and mapped between:

dark aurora color
mid aurora color
light aurora color

The original image is blended against this target palette using a blend factor controlled by the computed day/night value.

Performance / Limitations

Executed in the composite pass.
Entirely screen-space.
Affects all rendered scene colors except pixels intentionally excluded by depth checks.

Animated Cloud Tinting

Visual Effect

Clouds receive a subtle animated aurora coloration that cycles through green-teal, purple, and blue tones.

Implementation

gbuffers_clouds.fsh:

Samples the original cloud texture.
Generates a three-color cycle using frameTimeCounter.
Blends the aurora hue into the cloud color at a fixed intensity.

Transparent cloud pixels are discarded before processing.

Performance / Limitations

Lightweight per-pixel color modification.
Does not alter cloud geometry or movement.

Water Aurora Reflections

Visual Effect

Water surfaces receive a shifting teal-to-purple color reflection effect.

The effect becomes stronger with increasing skylight exposure.

Implementation

gbuffers_water.fsh:

Generates a two-color animated cycle.
Uses lmcoord.y as a skylight factor.
Blends the water color toward an aurora reflection tint.

Water transparency is also adjusted:

texColor.a = clamp(texColor.a * 1.5, 0.2, 0.75);

Performance / Limitations

Pure color manipulation.
No reflection tracing.
No wave simulation or water distortion.

Underwater and Lava Fog Tinting

Visual Effect

Additional color fog is applied when the camera is submerged in water or lava.

Implementation

The composite shader checks:

isEyeInWater

and blends the final image toward predefined water or lava colors.

Performance / Limitations

Simple color blend only.
No volumetric scattering.

Screen-Space Shimmer Modulation

Visual Effect

A subtle animated brightness fluctuation is visible across the image.

Implementation

Brightness is multiplied by a sine-based factor derived from:

screen-space Y position
frameTimeCounter

Both overworld and Nether composite passes use this technique.

Performance / Limitations

Extremely lightweight.
Pure post-processing effect.

Nether Aurora Color Pass

Visual Effect

The Nether receives a separate aurora-inspired color treatment using teal and violet tones.

Implementation

world-1/composite.fsh:

Computes scene luminance.
Generates a teal-to-violet gradient.
Multiplies the gradient by luminance.
Blends the result heavily into the final image.

Nearby hand/HUD pixels are excluded using depth testing.

Performance / Limitations

Entirely screen-space.
No Nether-specific sky rendering.

Hand Preservation

Visual Effect

The player's hand remains unaffected by most aurora post-processing.

Implementation

A dedicated hand buffer is configured through:

drawBuffers.gbuffers_hand=01

Composite shaders also exclude near-depth pixels (depth < 0.56) from aurora processing.

Performance / Limitations

Prevents excessive color grading on held items and first-person hand models.

Compatibility

Rendering Pipeline

OpenGL GLSL 1.20
Uses OptiFine-style shader stages:
- composite
- gbuffers_basic
- gbuffers_textured
- gbuffers_clouds
- gbuffers_water
- gbuffers_hand

Identifiable Requirements

Requires support for:
- colortex0
- depthtex0
- inverse projection matrices
- OptiFine-style gbuffer uniforms

Supported Loaders

The archive does not contain explicit metadata declaring supported loaders. Compatibility with specific loaders (OptiFine, Iris, etc.) cannot be confirmed from the project files alone.

Known Limitations

No configurable shader menu entries were found.
No shadow pipeline.
No deferred lighting system.
No volumetric effects.
No normal mapping or PBR features.

Shader Options / Configurable Settings

No user-configurable shader parameters were found.

The project contains only:

drawBuffers.gbuffers_hand=01

which is an internal buffer configuration rather than a user-facing setting.

Aurora Veil