The diffusion route generates at SDXL's native 1024px, so a 32px icon is a
32x downscale. Detail that survives the generator does not survive that
reduction -- a coin's struck emblem, a shield's radial pattern and a
lantern's glass panes all mush at 32px and read clearly at 64px.
max_colors is deliberately NOT scaled with the canvas. Measured over the 300
genuine 48x48 icons in ~/opengameart-downloads: p50=9 p90=13 max=14. A cap of
32 rejects 0.00% of that art and so does every larger cap, so hand-made art
does not spend more colours on a bigger canvas. Raising it would only admit
more un-quantized generator output.
Gates 18/18: the 12 original bake-off subjects re-finished at 64px, plus six
subjects the route had never seen (lantern, axe, boots, helmet, torch,
mushroom).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T9rQ12yZ7sJxiPQTCS5dUF
Blender defaults to the AgX view transform, a photoreal film emulation
that rolls off highlights and desaturates. On the flat-lit item renders
the 3D route produces, it turned gold into beige and washed out every
material -- which is why row C read as unusable in the bake-off.
Measured on an identical coin scene where only view_transform differed:
mean saturation 0.282 (AgX) vs 0.787 (Standard), a 2.8x increase.
This makes row C a fair test, not a good one: the geometry is still
low-poly primitives and ring/bone remain nearly invisible at 32px.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T9rQ12yZ7sJxiPQTCS5dUF
Closes the remaining bake-off cells. The phase's real result was not a route
score but a MISSING GATE.
All twelve SDXL icons measured 100% opaque coverage -- square tiles with no
sprite silhouette -- and passed every gate in the harness. Gate-pass was
measuring pipeline hygiene, not usability. MARGIN_TOO_SMALL inverts the table
from a meaningless 12/12/12 tie to:
diffusion 0/12 (every output full-bleed)
vector 10/12
procedural 11/12
The two non-diffusion failures were true positives in MY shapes, not gate
error: the procedural sword pommel ran off the bottom edge and the vector meat
bone clipped the top. Both fixed; both routes back to 12/12.
Diffusion recovers to 12/12 with flood-fill background removal, but visual
inspection shows the fill eats into the art (bone reduced to a fragment, sword
nearly erased). Reported as inadequate rather than shipped -- proper matting is
needed before route (b) is a usable pipeline.
Blender exits 0 even when its embedded script raises: BLENDER_EEVEE_NEXT does
not exist in 5.2, and the failure produced a clean exit and no file. render()
now asserts the output exists, or the route would report phantom successes.
Model gating verified at execution time, never recalled: SDXL base and
nerijs/pixel-art-xl are ungated, FLUX.1-dev is gated=auto, and
runwayml/stable-diffusion-v1-5 now 307-redirects.
The finishing stage now generalises across three continuous-tone sources
(SVG raster, Blender render, SDXL): each is 0/N raw and N/N finished.
Verified: 114 tests, 100% branch coverage on 13 modules, zero suppressions,
all hooks pass. Note: a local pytest run masked a missing branch that the
pre-commit hook caught -- the hook's run is authoritative.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T9rQ12yZ7sJxiPQTCS5dUF
Closes the two CPU-only cells of the art bake-off and builds the bridge the
diffusion cell will reuse.
Pins the bake-off to the SAME twelve subjects item-icons measured, with its
easy/hard split intact. Without this a route tested on distinctive silhouettes
beats the 6/12 baseline for free and the decision table means nothing. It also
makes the subject-routing rule falsifiable: a generator route is predicted to
lift specifically the six human-prior failures, and if it does not, the rule is
recorded as wrong.
Route (a) procedural: all twelve subjects drawn deterministically from a
7-colour locked palette. Every shape gets a distinguishing feature up front,
because item-icons measured that plain primitives read as placeholders however
correct the geometry is. Machine gate: 12/12 -- which proves "not malformed",
NOT quality. A procedural generator satisfies palette/alpha/canvas constraints
trivially; the human contact sheet is the real verdict.
Route (d) code-as-art: SVG emitted as text and rasterised by rsvg-convert, so
no new Python dependency (cairosvg/svgwrite stay absent).
The structural finding, measured on real rasteriser output rather than a
synthetic stand-in: raw vector renders pass 0/5 -- every one fails
ALPHA_NOT_BINARY, most also TOO_MANY_COLORS. After the finishing stage, 5/5.
Continuous-tone routes are therefore GENERATORS FEEDING A FINISHER, not
pixel-art generators. finish.py binarises alpha before quantising colour,
mirroring the gate order: quantising first blends transparent pixels' arbitrary
RGB into the palette.
Verified: 92 tests, 100% branch coverage across all ten modules, zero
suppressions, all hooks pass. The PLR2004 lint refactor was confirmed
pixel-neutral by byte-comparing all 12 icons before and after (12/12 identical).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T9rQ12yZ7sJxiPQTCS5dUF
Adds the route-independent spine of the planned art-generation bake-off: a
harness that decides whether generated art is well-formed, so "non-sloppy"
becomes machine-checkable instead of a judgement call.
Findings that shaped the design, all measured rather than assumed:
- Integer-scale invariance separates true pixel art (impurity 0.0000) from
interpolated fakes (1.0000) exactly -- but passes trivially at scale 1, so
it must never be trusted alone on native-resolution output.
- Gate ORDER is load-bearing. A soft-alpha image has no fully-opaque pixels,
so an opaque-only colour count returns 0 and silently passes. ALPHA_NOT_BINARY
now runs first and COLOR_COUNT fails closed on an empty opaque set.
- Counting must be over opaque RGB only: transparent pixels retain arbitrary
RGB and inflated a naive RGBA count, rejecting correct art at 18/16.
- Declaring a gate was not enough to run it. hand_painted.toml shipped
declaring SILHOUETTE_LOW_CONTRAST with no implementation, so it parsed, ran
nothing, and reported a pass. load_spec now fails closed on unimplemented
gates, result-only codes, and gates missing their config.
Thresholds are calibrated against 250 genuine 32x32 CC0 icons, not guessed:
p50=7 p90=13 p99=26 opaque colours; cap 32 rejects 0.0% of real art while raw
generator output measured 34403 colours. An initial cap of 16 wrongly rejected
a real DCSS icon -- re-derived from the corpus rather than nudged.
Verified: 57 tests, 100% branch coverage, zero suppressions, all hooks pass.
58/60 (96.7%) of real CC0 icons pass the full stack; both failures confirmed
true positives.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T9rQ12yZ7sJxiPQTCS5dUF
