Alpha Piscium is built around Physically Based Rendering from the ground up. Every lighting calculation — from emissive block glow to specular reflections and subsurface scattering — depends on accurate material data that vanilla Minecraft textures simply do not provide. Without a compatible PBR resource pack, emissive values are undefined for most blocks, which means the world will appear unnaturally dark at night and indoor spaces will lack the warm, glowing quality that PBR materials produce. Pairing Alpha Piscium with a proper PBR resource pack is the single most impactful step you can take to get the intended look.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/Luna5ama/alpha-piscium/llms.txt
Use this file to discover all available pages before exploring further.
Why PBR Matters
Standard Minecraft resource packs only ship a single color (albedo) texture per block face. PBR pipelines require at minimum three additional data channels:- Normal map — encodes per-pixel surface orientation to simulate fine geometric detail without extra geometry.
- Specular / roughness / metalness map — controls how light scatters off or reflects from a surface.
- Emissive map — marks pixels that emit light, allowing blocks like glowstone, sea lanterns, and shroomlights to actually illuminate their surroundings at night.
The PBR Material Mode Setting
TheSETTING_PBR_MATERIAL option controls how Alpha Piscium sources material data. It is found under Options → Video Settings → Shader Options → Terrain in-game and has three values:
Built-in (0)
Uses hardcoded PBR data for vanilla blocks. No resource pack required, but quality and coverage are limited to what is built into the shader.
LabPBR Auto (1)
Default. Automatically detects whether the active resource pack provides LabPBR-format textures and enables them if found. Falls back gracefully if no pack is detected.
LabPBR Force (2)
Forces LabPBR mode regardless of detection. Use this if your pack provides LabPBR data but the automatic detection does not activate it.
The default value is LabPBR (Auto). If you install a compatible resource pack and the shader does not seem to use it, try switching to LabPBR (Force) to override detection.
What Is LabPBR?
LabPBR is the community-standard format for encoding PBR material data inside Minecraft resource packs. It stores additional material information in the otherwise unused color channels of specially named textures:_ntextures (normal maps) — encode surface normals in the XY channels, ambient occlusion in the blue channel, and a heightmap in the alpha channel._stextures (specular maps) — encode roughness, metalness, emissive intensity, porosity, and subsurface scattering data packed into RGBA channels.
Recommended Resource Packs
The Alpha Piscium FAQ recommends two packs:SPBR
Recommended for players who want a vanilla-faithful style with proper PBR data. SPBR keeps Minecraft’s familiar block aesthetic while adding the normal, specular, and emissive maps that Alpha Piscium needs to render correctly.
Patrix
A higher-resolution, more realistic resource pack. Recommended if you prefer a detailed, non-vanilla look. Patrix ships full LabPBR support and pairs well with Alpha Piscium’s lighting pipeline.
Normal Mapping
Normal mapping adds surface depth and micro-detail to blocks without requiring additional geometry. Alpha Piscium reads normal maps from your LabPBR resource pack and applies them during lighting calculations.Enabling Normal Mapping
Normal mapping is controlled bySETTING_NORMAL_MAPPING, which is enabled by default. You can toggle it under Shader Options → Terrain → Normal Mapping.
Normal Mapping Strength
SETTING_NORMAL_MAPPING_STRENGTH adjusts the intensity of the normal map effect. The value is an exponent: the actual strength applied is 2^x. The default value is 0.0, meaning a multiplier of exactly 1.0 (no amplification or attenuation). Increasing the value exaggerates surface detail; decreasing it flattens it.
| Setting Value | Actual Multiplier | Effect |
|---|---|---|
-1.0 | 0.5× | Subtler surface detail |
0.0 | 1.0× | Default (pack’s native intensity) |
1.0 | 2.0× | More pronounced surface relief |
2.0 | 4.0× | Strong, exaggerated depth |
TBN Packing
SETTING_TBN_PACKING is a terrain rendering optimization that packs normal and tangent vertex attributes into a tighter format. It is enabled by default and is safe to leave on for most setups.
Setup Walkthrough
Download a compatible resource pack
Obtain SPBR (for vanilla style) or Patrix (for high-res), or any resource pack that ships LabPBR-format
_n and _s textures.Install the resource pack
Place the resource pack ZIP in your
.minecraft/resourcepacks folder and activate it via Options → Resource Packs in Minecraft.Load Alpha Piscium
Select Alpha Piscium from Options → Video Settings → Shader Packs and wait for it to compile.
Verify the PBR mode
Open Shader Options → Terrain and confirm that PBR Materials is set to LabPBR (Auto). If materials are not loading correctly, switch to LabPBR (Force).