ChunkScan

Paper/Spigot plugin that reads the InhabitedTime of every generated chunk straight from the region files (no chunks are loaded) and finds the smallest radius around a point that contains every chunk players have spent more than a given time in. Meant for cleaning up worlds that were pre-generated with Chunky before trimming them.

Usage

/chunkscan <minTime> [chunky | spawn [world] | origin [world] | here | <x> <z> [world]]

• minTime: 30s, 5m, 1h, 600t (ticks); a plain number means seconds. Chunks need an InhabitedTime strictly above this to count as visited.

• Center:

  • chunky – Chunky's current selection (/chunky world, /chunky center)
  • spawn [world] – the world spawn
  • origin [world] – 0, 0
  • here – your own position
  • <x> <z> [world] – a specific point
  • nothing – same as chunky, falling back to your position (or the spawn from the console) if Chunky isn't installed

  Without a world, the world you're in is used (the main world from the console).

Tab completion suggests the options.

Permission: chunkscan.use (op by default).

The scan uses every CPU core and is built for maintenance windows: run it when nobody is online. The world is saved first so loaded chunks are included.

Output

In chat:

• distribution of InhabitedTime over all generated chunks
• smallest circle and square radius (in blocks) that fully contain every visited chunk, the chunk that defines it, and how many chunks would be outside
• the /chunky command(s) to set that radius

In plugins/ChunkScan/:

• <world>-<time>.png – heatmap, one pixel per chunk, north up. Dark gray: generated but never visited, blue: visited below the threshold, yellow → red: above the threshold, green circle: suggested radius, white cross: center
• <world>-<time>.csv – every chunk with InhabitedTime > 0, sorted by time

Notes

• Supports gzip, zlib, uncompressed and external (.mcc) chunks, pre-1.18 and current chunk formats. LZ4-compressed chunks (region-file-compression=lz4) are counted but skipped.
• The radius covers the whole farthest chunk; Chunky's trim keeps a chunk when its center is inside the shape, so the suggested radius is slightly conservative.

Building

mvn package

The jar ends up in target/. GitHub Actions builds it on every push to master (or manually via "Run workflow"); download it from the run's artifacts. Pushes to dev are not built.

When the version in pom.xml has no release yet, the master build also publishes a GitHub release (v<version>) with the jar attached. Bump the version to publish the next one.