Selas

Selas is a client-side NeoForge mod for Minecraft 1.21.1.

It changes the vanilla lightmap to make nights, caves, rain, and thunder darker. The goal is natural, readable darkness rather than pure black voids. It does not add blocks, items, mobs, or dimensions.

What it changes

night brightness
cave darkness
rain and thunder darkness
moon phase brightness
day/night transition timing
minimum brightness floors
open-sky starlight floor
block light preservation
low-light desaturation
low-light cool tint
Nether and End lighting (warm Nether ambient, cool End ambient)
optional brightness-slider (gamma) handling
optional auto-disable while a shader pack is active

What it does not change

day length
mob spawning
server time
block light propagation
sky rendering
fog rendering
dynamic lights
blocks, items, mobs, or dimensions

Configuration

Selas generates a client config file:

config/selas-client.toml

The config is grouped into sections for general switches, dimensions, Nether/End lighting, twilight timing, moon/weather values, brightness, and color.

Selas does not use built-in presets. Values are changed directly in the config.

Compatibility notes

Selas is a visual client-side mod. It can be used on servers because it does not change server logic.

Shader packs usually replace vanilla lightmap lighting. By default Selas disables itself while an Iris/Oculus shader pack is active (disable_with_shaders). You can force it back on in the config if needed, but most packs will ignore or override the result.

Minecraft's vanilla lightmap and 16 raw light levels can also show visible texture grain during dusk and dawn; darker lighting can make this easier to see.

The brightness slider (respect_gamma) is off by default so nights and caves stay locked to Selas targets. A small residual slider effect may still appear in already-bright areas because vanilla applies gamma before Selas runs.