3.0.0 [26.2]

• Requires Java 25 and targets Paper 26.2. Chunky and VoidWorldGenerator are still used for pregeneration and out-of-bounds chunks; the configured setup step can download them.
• Existing configurations need migration: replace surfaceWorld.name and cavesWorld.name with worldPath and dimension in each section. The default source layout is <worldPath>/dimensions/minecraft/overworld/region; use regionPath for a different layout. Set surfaceWorld.entitiesPath when entity files cannot be resolved from the world and dimension.
• Reference-world entities can now be copied from entity region files into newly generated chunks. If no entity region directory is available, generation continues without copying them.
• Replace cache.size with cache.regionFiles (default 16) and cache.chunks (default 64). The chunk cache reduces repeated source-world reads; values below 32 may substantially slow generation.
• Use namespaced block, biome, and entity IDs in configuration, such as minecraft:sand and minecraft:item. Unqualified IDs use the minecraft namespace. Block and entity regex patterns now match complete namespaced IDs, so existing patterns should be reviewed.
• Block support and replacement cleanup now runs during generation, and entity removal runs when a newly generated chunk loads. Remove steps.cleaningBlocks and the previously misspelled steps.cleaingEntities from existing configurations; only steps.underillaGeneration needs to be reset to todo for a new generation pass.
• clean.blocks.removeUnstableBlocks now checks newly generated chunks after they load. The end-of-generation block transformer hook was removed; plugin integrations using it must be updated.
• vanillaPopulation.enabled now controls mob generation as well as feature generation.
• Improved terrain and cave merging, including filling gaps between a high reference surface and lower generated terrain when no separate caves world is supplied, and preserving configured reference terrain around cave carvers.
• The bundled biome-merging list now includes minecraft:sulfur_caves.
• Generation timings and aggregate statistics are written to plugins/Underilla/metrics.json during generation and on shutdown.
• The bundled example datapacks and test worlds have been removed. Bring your own datapack when customizing vanilla features or cave generation.
• The Java integration packages moved from fr.formiko.mc.underilla to com.kntrel.mc.underilla; downstream plugins and libraries must update their imports. The project now builds separate core and Paper modules.
• Pushes to main build and run tests. When the project version increases, the release workflow creates a v tag and publishes the JAR to GitHub Releases and Hangar. Modrinth and Maven Central publishing are no longer configured.