Altheon Shaders

Altheon Shaders

by Kefir_twtch

Torches glow orange, soul lanterns glow cyan, and the sky is physically real.
Altheon is a realistic shaderpack for Iris. It is built around colored block lighting, volumetric clouds and a physically based atmosphere.

Requires Iris 1.6+ (Fabric/Quilt + Sodium). OptiFine is not supported.

Colored block lighting

Every light source has its own color, and the colors mix where their light overlaps. Light spreads through a voxel volume around the player, so it flows around corners, stays out of sealed rooms and picks up the color of stained glass. Surfaces facing a light are lit brighter than those turned away.

• Torches, lanterns and campfires give warm orange light
• Soul torches and soul lanterns give icy cyan light
• Froglights, amethyst, lava, sea lanterns, glow lichen and redstone each have their own color
• Colored handheld light: hold a soul lantern and the world around you turns blue

Sky, clouds & atmosphere

• Physically based sky (Rayleigh, Mie and ozone scattering) with deep red sunsets and violet twilight
• Volumetric cumulus clouds: flat bottoms, silver linings, real shadows on the ground
• Volumetric light rays and height fog, with distant mountains fading into blue haze
• Starry nights with moonlit clouds

Shadows & light

• Contact-hardening shadows (PCSS): sharp where an object touches the ground, softer further away
• Colored shadows cast through stained glass
• Warm bounced sunlight, so shade looks alive instead of grey
• SSAO in corners and crevices
• Foliage translucency: leaves and grass glow when the sun is behind them

Water & materials

• Water with waves, refraction, depth absorption (turquoise shallows, deep blue depths) and screen-space reflections
• Rain puddles and wet surfaces that reflect the world
• Auto-generated block relief (normal maps) on every texture
• Auto PBR: shiny metals and polished stone, glowing ores in caves
• Waving grass, flowers, crops, leaves and vines

Image quality

• Temporal anti-aliasing (TAA) with sharpening: no jaggies, no shimmering
• AgX tonemapping (ACES and Lottes also available), bloom, eye adaptation, white balance

Settings & performance

More than 100 options with full English and Russian translations, plus 4 quality presets:

Preset · Recommended GPU
Low · GTX 1060 / RX 580
Medium · GTX 1660 / RTX 2060
High (default) · RTX 3060 / RX 6600 and up
Ultra · RTX 3080 / RX 6800 and up

Every major effect can be switched off on its own: colored lighting, clouds, god rays, reflections, SSAO, TAA and more.

Installation

1. Install Fabric (or Quilt), Sodium and Iris for Minecraft 1.20.1+.
2. Drop the .zip into .minecraft/shaderpacks/. Do not unzip it.
3. In the game open Options → Video Settings → Shader Packs and select Altheon Shaders.
4. Pick a preset under Shader Pack Settings.

Found a bug?

Please report your GPU, your Minecraft and Iris versions, a screenshot and .minecraft/logs/latest.log.

License

All Rights Reserved © 2026 Kefir_twtch

You may play the pack, record videos and streams, and include it in modpacks via a link to this page.
Re-uploading, redistributing or publishing modified versions is not allowed.

Full terms are in LICENSE.txt inside the pack.