Lathe

Lathe makes slabs, vertical slabs, stairs, vertical stairs and corners for the blocks you choose, from any mod. List the blocks in a small rules file and each one gets real shaped blocks that look, sound and mine like the original, with recipes, drops and tags. It's for modpacks whose builders and city palettes need shapes that the block's own mod never added.

Requirements

Choosing Blocks

One line per block in config/lathe/, the shapes first:

# Shapes vanilla doesn't have
slab stairs vslab vstairs corners minecraft:calcite
slab vslab minecraft:*_concrete
slab vstairs minecraft:glass nocombine

• Globs: minecraft:*_concrete covers a whole family.
• nocombine: two slabs of that block never merge into a double slab.
• Mistakes are warnings: an unknown block or a block that isn't a full cube is skipped with a line in the log, not a crash.

NOTE: removing a rule removes its blocks from worlds that have them. Treat rule changes like adding or removing a mod.

Placing And Breaking

• Slabs go where you aim: the middle of a floor makes a bottom slab and its edge a vertical slab against that edge; on a wall, the middle makes a vertical slab against the wall and the top or bottom edge a top or bottom slab.
• One slab item places both kinds, when a block has both.
• Vertical stairs open toward you, on the side you aim at.
• Corners fill the gap where stairs and vertical stairs meet: the piece that fits where they overlap, or, sneaking, the piece that covers both. With nothing to fit, the corner goes where you aim.
• Double slabs break one half at a time, and the outline shows which half.
• An outline previews the piece you're about to place.

Screenshots

Vertical Slabs And Stairs BetterBlockZ's Lab Link Base	Glowing Blocks Stay Bright BetterBlockZ's Cyber Light
Slabs And Stairs A BetterBlockZ pillar block, original on the left	Stair Corners And Vertical Stairs The same block, turned every way
Outer Corner Upside-down stairs meeting vertical stairs	Inner Corner The same gap, placed while sneaking

Shown with Embeddium, Oculus and a shader pack.

Lost Cities

Every shape has an id that never changes, like lathe:minecraft__calcite_stairs, so Lost Cities palettes can use them with a state ([facing=north,half=bottom]). Stairs, vertical slabs, vertical stairs and corners turn with the parts Lost Cities rotates. Corners never change shape when their neighbours change, so they stay as the palette says.

Inspiration

Placing by aim follows AutoSlabs by Andrew6rant, and breaking one half of a double slab follows KleeSlabs by BlayTheNinth.