Build GLBs from recipes

manfred build turns a recipe into the files a game or an app loads. It is CPU only: no GPU, no window, no clock and no randomness beyond the recipe’s seed, so the same recipe gives the same bytes on any machine and a changed GLB in a diff is a changed scene.

What a build writes

The recipe’s [output] table names the files, relative to the recipe:

[output]
glb = "scene/desk.glb"
sidecar = "scene/desk.json"
sidecar_dialect = "facts"
bake = "assets/bake.toml"
scene = "scene/desk.scene.toml"

• glb: the meshes, their materials by name, the node tree. Without it the build writes <name>.glb.
• sidecar with sidecar_dialect: the cameras, sun, sky, look and movers as JSON. facts is Manfred’s own dialect; an app’s build binary can register its own.
• bake: a pfx bake recipe for the scene, with the same sky, sun and files.
• scene: the engine’s runtime scene file, which the window and pfx open.

--out <dir> writes every file into one folder instead:

$ manfred build showcase/workshop.toml --out out
out/workshop.glb

Each path written is printed on stdout.

Variants

A variant is a named change to the recipe, built into its own files:

[variant.bare]
drop = ["slat*", "wall_*", "vase"]
set = { "sun.irradiance" = 0.0 }
remove = ["light.lamp"]

manfred build desk.toml --variant bare     # writes desk-bare.glb and desk-bare.json
manfred build desk.toml --all-variants     # the recipe, then every variant in name order

drop removes objects by glob; set and remove take dotted paths, with an entry of an array of tables addressed by its name (camera.main.fov_y_deg, light.lamp). A variant’s name goes before the last extension of each file name, unless [variant.<name>.output] names its files.

One-off overrides

--set key=value replaces a value the recipe already has, for that run only; the file is never written. build, shot, render and clip take it, as often as needed:

$ manfred build desk.toml --set object.ball.radius=0.08 --out big
big/desk.glb
big/desk.json

The value takes the kind of the one it replaces. A key the recipe does not carry is refused in one line, exit 1; a missing = is a line Manfred cannot parse, exit 2.

Problems

manfred check and manfred build report a problem at its line, naming the key, and exit 1:

$ manfred build showcase/workshop.toml --variant nonesuch --out out
manfred build: showcase/workshop.toml: variant.nonesuch: no such variant, the recipe has no variants

Compare two builds

manfred diff compares two GLBs by structure, node by node:

$ manfred diff out/desk.glb big/desk.glb
~ ball
    bounds [0.1000 -0.0000 -0.0000]..[0.2000 0.1000 0.1000] -> [0.0700 -0.0300 -0.0300]..[0.2300 0.1300 0.1300]
    area 0.031388 -> 0.080353

It exits 0 with no differences beyond tolerance when they match and 1 when they differ. --json prints the same report as JSON (file formats). --render --recipe <recipe> also draws both GLBs alike through the recipe’s camera and compares the pictures by PSNR, failing under --floor (35 dB by default):

manfred diff out/desk.glb big/desk.glb --render --recipe desk.toml --camera main