logan
769af6fa2d
The swap does not carry players' explored terrain across. FTB Chunks stores no rendered map (its region zips hold chunks.dat plus five data PNGs, one of which packs height into an image channel), and Xaero's region format is closed and now version 6 with per-pixel NBT blobs, so the community converters no longer work. Rather than convert pixels, prune a copy of the world save down to exactly the chunks a player revealed and let Xaero's own generator map it. Validated against real data: extracting the 167-region / 98,170-chunk mask cross-checks clean against FTB's own pixel data, and Anvil pruning round-trips byte-identically (15.7 MB -> 471 KB on a live region file, slot-to-chunk mapping confirmed against 1024 chunk NBT headers). Deferred for now: needs the world save and one singleplayer pass per player. See analysis/FTB-XAERO-MAP-MIGRATION.md.