# Provenance: Warbirds P-51D-20-NA hero model

Owner's asset, rebuilt procedurally in this folder. No geometry, UV layout, texture or livery art
from any third-party model is used; the FlightGear P-51D (GPL-2.0-or-later) previously used on the site
was only viewed as rendered captures (the evaluator's `fg-opponent` run) to understand the
competition. It was never imported, measured, traced or sampled.

## Shape and dimensions
- Lines digitised by hand (pixel coordinates in `lines.py`) from the public-domain U.S. military
  3-view of the P-51D (NAA drawing 106-00001), Wikimedia Commons
  `File:North_American_P-51D_Mustang_3-view_line_drawing.png`, local copy
  `research/p51-refs/ref13_p51d-3view-line-drawing_usmil_PD.png`.
- Scaled to published dimensions: length 32 ft 3-5/16 in (9.838 m), span 37 ft 5/16 in
  (11.285 m), propeller 11 ft 2 in (3.40 m, Hamilton Standard 24D50), tailplane span 13 ft 2-1/8 in.
- Details (exhaust shroud, canopy framing, gun ports, panel layout, rivet rows, stencil block) were
  modelled/painted from observation of CC0 Smithsonian NASM photographs (NASM2018-10346, -10348,
  -10476) and public-domain USAAF/NASA photographs listed in `research/p51-refs/asset-brief.md`;
  nothing is traced or sampled from them.

## Livery: P-51D-20-NA 44-72218 "Big Beautiful Doll", WZ-I, 84th FS / 78th FG (Col. John D. Landers)
- Chosen by the owner 2026-09-26. Facts and sources: see "Livery research" below.
- All markings are drawn by `paint_livery.py` from parameters in `livery_spec.py`: star-and-bar to
  the AN-I-9b construction (vector polygons), USAAF-style block code letters (hand-defined polygons),
  serial in DIN Condensed Bold (macOS system font), data-block stencils in DIN Condensed Bold, the
  name in Brush Script (macOS system font). No kill markings with swastikas are rendered.

## Software
Blender 5.0.1 (build, Cycles bakes, glTF export), numpy/OpenCV/Pillow (painting), glTF-Transform 4
(WebP, meshopt).

## Livery research (Paint State C, May-June 1945)
Facts come from a research pass over wartime photographs and modern references
(`/private/tmp/claude-501/p51/bbd-livery-spec.md`, 2026-09-26). Only the NARA photograph is public
domain and is kept locally for reference (untracked):
`research/p51-refs/bbd/bbd01_44-72218-landers-cockpit-24mar1945_usaaf-56813AC-NARA-204877099_PD.jpg`
(NARA 56813AC, https://catalog.archives.gov/id/204877099). IWM Roger Freeman Collection photographs
(FRE 13402, 10767, 2983, 2982, 2987, 268, 275) were viewed and cited for facts only, never copied.
Modern references: Eduard 82102/2147 instructions, Lifelike Decals 48-051/32-020 notes (IPMS review).

Implemented from those facts (all drawn procedurally, see `livery_spec.py`):
- 78th FG black/white checkerboard over the whole engine cowling, 8 checks along (~7.5 in), 16 around,
  aligned to the cowl panel joints, black just left of the top centreline in the first row; Insignia
  Red band (2.5 in) along its aft edge.
- Spinner split into black (pilot's left) and white halves through two opposite blade roots, red ring
  at the back plate.
- Olive Drab 41 anti-glare panel from the red band to the windscreen, straight lower edge, thin red line.
- Rudder solid black (84th FS); fin and tailplane tips black with red trim; wingtips checkered on the
  upper surface with red trim; flaps and ailerons unpainted metal; wings aluminium lacquer.
- 30 in fuselage and 35 in wing star-and-bars (AN-I-9b construction); codes WZ (forward of the star)
  and I (aft, midway to the tailplane) in 19 in black block letters with a thin red outline.
- Serial 472218 on the fin forward of the rudder hinge; "Big Beautiful Doll" in black brush script with
  a white outline and a red drop shadow on both sides; "Col. J.D. Landers" name plate (left side);
  white-on-black data block; red antenna mast and carburettor intake lip.
- Kill tally omitted entirely (owner rule), leaving bare metal.