Pulsar Lighting Engine

This is a mod exclusively for Cleanroom. It requires Java 25 and Cleanroom 0.6.10 or later.

Pulsar is an asynchronous lighting engine built for Cleanroom. It reimplements Starlight-style algorithms for Cleanroom and runs lighting calculations on separate threads.

Requirements

• Cleanroom 0.6.10-alpha or newer

Features

• Runs server-side light propagation on separate threads.
• Batches large groups of block changes instead of processing lighting separately for every edit.
• Caches light data in each chunk's NBT to avoid unnecessary full relights.
• Keeps Vanilla's block-light and sky-light data synchronized, so removing Pulsar does not corrupt your world.
• Includes various lighting bug fixes and quality-of-life improvements.
• Adds natural lighting to Thaumcraft crystals.
• Fully compatible with rendering mods such as Celeritas, Actinium, and Nothirium.

Fixed Bugs

• MC-92
• MC-1531 — smooth lighting across painting tile boundaries.
• MC-3329
• MC-80966
• MC-104532
• MC-116690
• MC-117067
• MC-117094
• MC-249343

Supported Mods

• Celeritas: fixes lighting bugs involving stairs and slabs.
• Fluidlogged API
• Depths Update: supports dimensions extending below Y=0 or above Y=255.
• JSON Paintings: fixes smooth-lighting bugs affecting paintings.

Incompatible

• Alfheim
• Phosphor for Forge
• Hesperus
• Other Starlight backports or mods that replace or rewrite the lighting engine
• The standard edition of The Aether II, which bundles Phosphor. Use The Aether II: Phosphor Not Included instead.

Unsupported or Untested

• CubicChunks
• OptiFine

Performance

Pulsar 0.5.0 Benchmarks

Block Placement and Removal

!Block update completion time

Sky Opening and Closing

!Sky opening and closing completion time

Server Load During Continuous Editing

These values measure main-thread MSPT. Async worker CPU time is not included.

!Main-thread MSPT during continuous editing

Flat Terrain Generation

!Equal-output flat terrain generation

Travel in a Flat World

!Server chunk readiness at travel destinations

Credits

• Starlight by Spottedleaf: the algorithms on which Pulsar is based.
• SuperNova by GTNewHorizons: an RGB lighting engine inspired by Starlight.
• Alfheim by Red Studio: a reference for directional neighbor brightness, liquid and emissive-block rendering, and light-only chunk packet handling.
• CleanroomModTemplate, TokenEnvoy, and CleanroomVersioning by CleanroomMC.

AI Disclosure

Pulsar uses LLM assistance in the following areas:

• Some code: primarily understanding and implementing algorithms.
• Translation and writing: translating into other languages and generating documentation.

License

Pulsar is licensed under the LGPL-3.0.