Arnis Meld Fork v2.9.2

Two themes: load your own tree models, and shape the terrain.

This release adds a schematic tree-pack system and two terrain knobs on top of the 2.9.1 generator. The build stays pack-agnostic: it ships no tree art, it just places whatever pack directory you point it at.

New

• Schematic tree packs (--tree-pack <dir>). Point Arnis at a directory of Sponge .schem tree models plus a region.json manifest and it places those models instead of the built-in procedural trees. The engine picks a realm by location, a community by terrain, then a weighted species, with a vanilla-tree blend mixed in. Models are stamped inside Arnis's own tree-spawn pass, so density and clearings stay natural.
• Trunk-width rarity and spacing. Trees are classed by trunk width and placed on a tiered rarity curve (thin common, wide rare), with a minimum trunk-spacing slot so fat trunks never crowd. Trees with very wide tops are kept rare rather than dominating a forest.
• Size by scale (--tree-sizes small,medium,big,tall,giant). Choose which height tiers may place. A disabled tier falls back to a smaller one, never a gap. Large tiers are gated off on small scales, so a 1:N city does not sprout 40-block giants.
• Reliable anchoring (float fix). Trees anchor on slopes and at water edges instead of floating; trees never root in water; bank canopy may overhang the shoreline; trees never clip into buildings.
• Vertical exaggeration (--vertical-exaggeration <factor>). Multiplies terrain height only, not the map footprint, so relief that flattens at small scales comes back. Auto-compresses to the build height. Default 1.0.
• Snow modes (--snow-mode off|realistic|peaks|manual, with --snow-percent and --snow-y). Off, the real latitude snow line, the top N percent of world height, or above a fixed Y.

Fixed and improved

• Water. Scale-aware small-scale river and pool depth (a linear bowl below scale 0.5), line-river width scale-capped so 1:10 streams stay 3 blocks or under, and a more varied riverbed. Trees and leaves are swept off the water surface so the waterline stays clean.
• --no-buildings. Also skips street-furniture nodes (lampposts, signs, traffic signals), not just building footprints.

Used by Meld

Meld ships a ready-made region pack built on this system: 1,959 hand-made tree models across 448 species and 10 world regions (172 communities, 3,900+ region placements), auto-selected by real-world location. This fork stays pack-agnostic and bundles none of that art, point --tree-pack at any compatible pack to use your own.

Notes

• No tree art is bundled. The pack format is a directory of .schem files plus a region.json manifest; pass it with --tree-pack. Without the flag, Arnis uses its built-in procedural trees exactly as before.
• No breaking flag changes. Worlds built without the new flags match 2.9.1 output.