Models, depth and sheets

The command line can rise one picture, layer or roll into a glTF model, give variants depth from a picture, snap soft edges, and read or set the grid a spritesheet carries. For what depth means, see Depth: paper, front and back.

Make one model

nfty model sprite.png --out sprite.glb                       # flat paper
nfty model sprite.png --out sprite.glb --front 2 --back 1    # every solid pixel 4 voxels thick
nfty model hat.igt --variant red --out hat.gltf --format gltf
nfty model chest.rcp --seed launch --out chest.glb

The input picks the form:

Input	Needs	Depth comes from
.png	Nothing else	Paper, unless --front and --back fill it
.igt	--variant <id>	The variant's stored depth (or --front/--back)
.rcp	--seed <text>	Each layer's stored depth, combined. The same roll nfty preview x.rcp --seed shows.

Option	Does
--out	The model to write. Required; its extension must match the format.
--front N --back M	Fill-all: every opaque pixel gets this depth (0 to 255), replacing stored depth. Both or neither; not on an .rcp.
--format	glb (default), gltf (writes a .bin beside it) or gltf-embedded.
--pivot	bottom-center (default), center or min-corner.
--voxel-size	World units per pixel, 0.001 to 1000 (default 1).

A Dynamic or Static variant rises as its stored gray value-map; there is no color option, because color is decided when an asset is cooked. A picture with a partly transparent pixel is refused, naming it. To model every asset of a collection, use generate --models.

Give a variant depth from a picture

nfty set depth chest.igt --variant stone --map stone-depth.png

In the map, red is the front depth and green the back depth, 0 to 255 voxels each; blue and alpha are ignored. The map must be exactly the variant's size. Depth over clear pixels is dropped, and an all-zero map clears the variant back to flat paper. Other variants are untouched. This is how the demo CookBook's relief is authored.

Snap soft edges

nfty inspect book.cbk --voxel              # which variants carry partial alpha
nfty set voxel-ready book.cbk --dry-run    # what a snap would change
nfty set voxel-ready book.cbk              # snap: >= 50% alpha solid, below clear

Read or set a spritesheet's grid

nfty sheet grid sheet.png                  # the embedded grid (or none) and the detected one
nfty sheet grid sheet.png --cols 8 --rows 4
nfty sheet grid sheet.png --cell 64x64
nfty sheet grid sheet.png --clear

Writing or clearing rewrites the PNG in place, keeping every pixel. --cols and --rows go together; --cell is the other way to say the same grid. A grid that does not divide the picture is refused. nfty export --sheet writes a sheet that already carries its grid. See Rise a spritesheet.