Sunwell

A portable hole in the ceiling — real sky light underground, on your terms.

Sunwell adds craftable Sunwell Lanterns that project true Minecraft sky light into enclosed spaces: crops grow, Dynamic Trees survive, daylight sensors respond, and rain can fall through — like open sky, but you hang it from a ceiling.

Pack makers get a tag-driven sunwell engine: register any block as a simple grow lamp, a full weather-aware sunwell, or anything in between — no Java required.

Sunwell concept art

What makes this different

Feature	Sunwell Lantern	Torch / Glowstone
Light type	Sky light (what plants check)	Block light only
Grows Dynamic Trees	Yes (≥ 12 sky light)	No
Daylight sensors	Yes, when exposed to day	No
Undead sun-burn	Optional (tag + config)	No
Weather & time	Optional (tag + config)	Always on
Mob spawns	Suppressed in lit region (configurable)	Normal rules

Blocks included

Sunwell Lantern renders

Sunwell Lantern

Vanilla lantern placement — floor or hanging from a ceiling
Emits block light 15 so the room stays usable at night
Projects virtual sky light below (full tag profile: day/night, weather, rain, burn)
Animated glow, flame, and ambient hum on the client
Recipe: quartz + iron bars + glowstone + glass

Soulwell Lantern

Soul-lantern variant with block light 10
Same sunwell behavior and tag profile as the Sunwell Lantern
Recipe: quartz + iron bars + soul sand + glass

Tag-driven behavior (for modpacks)

Every sunwell block needs #sunwell:sunwell_source. That alone gives a static grow light — always-on virtual sky at skyLevel, no undead burn, no weather dimming, no rain.

Opt in to extra behavior with additional tags:

Tag	Effect
`sunwell:sunwell_source`	Required. Flood-fills virtual sky light for crops & trees
`sunwell:dynamic_exposure`	Light follows day/night, surface sky, weather, and gentle lantern flux
`sunwell:undead_burning`	Undead can sun-burn in the lit region during the day
`sunwell:rain_through`	Rain and snow fall through the region during weather

Default mod lanterns ship with all four tags. Pack integrations (for example Liminal Industries ceiling lamps and blockofsky:sky_block) can use sunwell_source only — underground farms without burning your base or flickering light.

Datapack — static grow lamp

{
  "replace": false,
  "values": [
    "yourmod:ceiling_lamp"
  ]
}

File: data/sunwell/tags/blocks/sunwell_source.json

KubeJS — static grow lamp

ServerEvents.tags('block', event => {
  event.add('sunwell:sunwell_source', 'kubejs:ceiling_lamp')
  event.add('sunwell:sunwell_source', 'blockofsky:sky_block')
})

KubeJS — full sunwell behavior

ServerEvents.tags('block', event => {
  const block = 'yourmod:solar_panel'
  event.add('sunwell:sunwell_source', block)
  event.add('sunwell:dynamic_exposure', block)
  event.add('sunwell:undead_burning', block)
  event.add('sunwell:rain_through', block)
})

Global config toggles (enableUndeadBurning, respondToWeather, and so on) still act as master switches — tags grant capability; config can disable it pack-wide.

How it works

Place a Sunwell Lantern (or any tagged block) on a ceiling.
The mod flood-fills open air below, stopping at solid blocks.
Inside that region, sky light is raised to a configurable level (default 14).
Blocks with dynamic_exposure dim and brighten with the outside world; static sources stay at full grow strength around the clock.
Block light from the lantern itself keeps the room lit after dark.

Performance: bounded flood-fill with per-tick chunk and node budgets, chunk caching, and adaptive batch sizing — designed for dense lamp layouts in large underground builds.

Configuration

config/sunwell-server.toml

Region

Option	Default	Description
`maxRadius`	12	Horizontal spread from each source (blocks)
`maxDepth`	24	Maximum depth below a source (blocks)

Light

Option	Default	Description
`skyLevel`	14	Virtual sky brightness (14 grows everything; 15 triggers vanilla `canSeeSky`)
`attenuateByDepth`	false	Light falls off with distance from the source

Behavior

Option	Default	Description
`followDayNightCycle`	true	Dim sunwell light at night for dynamic_exposure sources
`respondToWeather`	true	Rain and storms dim dynamic_exposure sources
`respondToSurfaceLight`	true	Tie strength to real outdoor sky above the column
`lanternFlux`	true	Subtle flicker on dynamic_exposure sources (matches lantern VFX)
`allowRainThrough`	true	Master switch for rain/snow through `rain_through` tags
`enableUndeadBurning`	true	Master switch for undead burn on `undead_burning` tags
`blockHostileSpawns`	true	Block monster spawns inside any lit region

Performance

Option	Default	Description
`nodeBudgetPerTick`	40000	Flood-fill cell budget per tick
`chunkBudgetPerTick`	24	Chunks rebuilt per tick

Tips

Always-on grow rooms: tag blocks with sunwell_source only, or set followDayNightCycle = false on dynamic sources.
Safe undead farms under lamps: omit undead_burning, or set enableUndeadBurning = false.
Keep skyLevel at 14 unless you explicitly need vanilla canSeeSky() (15).

Supported versions

Minecraft	Forge	Java	Status
1.20.1	47.4+	17	Supported

Other Minecraft or Forge versions are not supported by this release.

Credits & license

Sunwell is an original mod by SdataG — all code, block models, textures, and client VFX were written and authored for this project. No assets or textures were ported from any prior mod.

The general idea of a ceiling-mounted virtual skylight lantern is familiar in the modding community (including older projects such as Ferreus Veritas's Skylight Lanterns); Sunwell is an independent reimplementation with its own architecture: tag-driven profiles, exposure system, rain-through weather hooks, performance budgets, soul variant, and client presentation.

License: MIT

SunWell