Spudlight Shaders

A lightweight GLSL shader pack with basic shadows, god rays, and waving leaves/water, tuned for low-end GPUs.

What it adds

• Soft directional shadows, capped to a small map size and short distance so the shadow pass stays cheap
• God rays - a screen-space light shaft effect from the sun/moon, not an expensive volumetric raymarch
• Waving leaves, plants, and water - vertex-shader effects with effectively no performance cost
• Underwater tint and a subtle vignette

What it deliberately leaves out

No SSAO, bloom, screen-space reflections, volumetric clouds, or TAA. These are the most expensive effects a shader pack can add, and they hit low-VRAM, low-bandwidth GPUs the hardest, so this pack skips them rather than shipping them just disabled.

Requirements

• Minecraft 1.26.2, Fabric loader
• Iris Shaders (this pack uses standard GLSL/OpenGL, no Vulkan requirement)

This is a modified fork of "Mellow" by TheCMK. The original engine, lighting model, shadow filtering, and cloud/water code are TheCMK's work; this fork only retunes defaults and adds one profile for low-end hardware. Per TheCMK's explicit permission (linked below), this fork does not use the "Mellow" name or its assets/screenshots.

What changed from upstream Mellow

1. Added a new profile, POTATO, in shaders.properties. It's now the pack's effective default (the underlying #defines in shaders/lib/settings.glsl were changed to match it, not just added as a selectable profile).
2. Default state changed in shaders/lib/settings.glsl:
   • BLOOM: on → off (multi-pass blur chain, composite2-7)
   • REFLECTIONS: 3 → 0 (ray-marched SSR was the single most expensive default the pack shipped with)
   • PBR_SPECULAR_RP_REFLECTIONS: on → off (redundant with REFLECTIONS=0)
   • CLOUD_STYLE: 1 → 0 (drops the 3D worley/perlin noise sample per cloud pixel in favor of vanilla flat clouds)
   • AURORA_BOREALIS: on → off (not part of the requested feature set)
   • DYNAMIC_SHADOWS: off → ON, at shadowMapResolution=512 (lowest) and shadowDistance lowered 96 → 64 blocks (basic shadows were a requested feature, so they're on, just capped hard)
   • GODRAYS: off → ON at GODRAYS_QUALITY=2 (lowest step; also requested)
   • Everything already off by default upstream (SSAO, SMAA, TAA, DOF, chromatic aberration, motion blur, outline, sharpening) was left off.
   • Wavy leaves/plants/water were already on by default upstream and were left untouched - they're vertex-shader-only and effectively free.
3. Renamed the in-game credit line and one settings comment in all three lang files (en_US, fr_FR, zh_CN) from "Mellow" to "Spudlight", per TheCMK's request.

What was not touched

The shadow-sampling code, lighting model, water rendering, cloud rendering, and every other GLSL file are unmodified from upstream Mellow. This fork is a defaults/config change, not a rewrite - all the credit for how any of this actually renders belongs to TheCMK. You can still access every other quality level (FAST/FANCY/FABULOUS, or any individual option) from the in-game shader settings screen - POTATO is just what loads first.

Permission and attribution

• Original pack: Mellow by TheCMK
• Explicit permission granted: Codeberg issue #211