Error messages

What nfty says, what it means, and what to do. Messages are written to be read -- the app never shows a stack trace unless you ask for one with --verbose.

"This image is 256x256; the canvas is 512x512."

Every drawing in a project shares one canvas size, and nfty will not resize your art.

Fix: re-export at the right size. See Why nfty never resizes your art.

"...allows exactly N unique assets, but M were requested."

The book cannot make that many distinct assets. The message states the real maximum.

Fix: add variants, widen a hue range, or make the quantize steps finer. See Raise the unique-asset count.

A rule conflict

The Recipe's rules exclude every combination, so there is nothing legal left to roll. This is not the same as the message above -- there the space was real and too small, here it is empty.

Fix: remove or loosen a rule. See Stop two traits appearing together.

"the reroll budget ran out"

nfty tried and failed to find a legal, unique roll within its per-asset budget. The space exists; it is just hard to hit at random.

Fix: raise --max-rerolls, or loosen whatever is making legal rolls rare.

"Recipe X has two ingredients named Y."

Two layers in one Recipe share a name. A layer's name becomes the trait_type in the published metadata, so two of them would merge into one trait and one rarity bucket -- which is how a collection ships percentages above 100%.

Fix: rename one. The same applies to the reserved name Type, which is used for the Recipe.

"Unsupported schema version"

The file was written by a newer build of nfty than the one you are running. nfty reads its own version and older ones, and refuses newer ones rather than misreading them.

Fix: update nfty.

Validation lists several problems at once

That is deliberate. validate reports everything it finds rather than stopping at the first, so you can fix them in one pass.

A layer is not showing up in the output

Not an error message, but the most common surprise.

Check: the variant's weight -- at 0 it is shelved. Then the Recipe's rules, which may be excluding it more often than you intended.

Your art looks blurry

It should not. nfty never smooths, resamples or anti-aliases anywhere -- editor, previews or output.

Check: the source art, and then partial transparency. See Use soft edges and run nfty inspect yourbook.cbk --voxel.