fcd-assets

name	fcd-assets
description	Regenerating fcd data, in particular ship-avatar marginMagic values via fcd/gen-shipavatar.js. Use when editing anything under fcd/, when asked to regenerate or fix ship avatar crops, or when ship portraits in the fleet view are framed wrongly.

fcd Assets — Ship Avatar Generation

fcd/gen-shipavatar.js generates the marginMagic values in fcd/shipavatar.json, which control how each ship's remodel art is cropped into an avatar.

Two methods — use banner

--method banner (the default) substantially outperforms --method face:

• banner: the game's 160x40 banner art is the game's own face-framed crop of the remodel art. The script registers banner -> remodel via ORB keypoints + RANSAC (scale + translation, no rotation); marginMagic is then linear in the transform (tx, s), and the two-feature least-squares fit implicitly finds the anchor (~x = 101px in the banner). Full run: R^2 = 0.82, MAE = 0.059, 4 failures out of 1724.

  The banner frame is removed by a cross-banner pixel-identity mask: background pixels are byte-identical across banners of the same stype, so >= 4 matches within +-2 marks background; the pool falls back to all banners for stypes < 6. Note that banner character scale varies per ship (2.15x–2.98x), so plain template matching fails; whole-banner matching also fails, because the banner band covers more vertical content than the remodel strip.

• face: lbpcascade_animeface. Pad 48px first (faces touch the strip edges) and do not use equalizeHist (the transparent-black background kills it). R^2 = 0.67, MAE = 0.073, 253 failures, with catastrophic outliers.

Workflow

node fcd/gen-shipavatar.js --start2 <api_start2 capture>   # default: fill missing/partial only
node fcd/gen-shipavatar.js --start2 <capture> --overwrite   # replace all
node fcd/gen-shipavatar.js --start2 <capture> --write       # merge into fcd/shipavatar.json
cd fcd && node build.js

The api_start2 capture comes from the response-saver — see the redux-api-testing skill.

Review the results in fcd/.cache/review.html before using --write. fcd/report-diff.js produces a before/after comparison against git HEAD with visual crops in fcd/.cache/diff-report.html.

Visual spot-check trick: bitblt the source-space window crop (x = m * 80 / (83/182), w ~ 325) out of the remodel PNG and view it.

Calibration warning

The fit is calibrated against the current fcd/shipavatar.json. Once machine-generated values are committed, that ground truth is polluted — if you recalibrate, fit against a hand-tuned revision instead:

git show <hand-tuned-rev>:fcd/shipavatar.json

Environment notes

• CDN: the legacy IP 203.104.209.71 is dead — use w01y.kancolle-server.com.
• Remodel art is 998x182; the 182 matches avatar.tsx's (height / 176) * 182.
• devDeps: opencv-wasm (has ORB / BFMatcher / CascadeClassifier but no estimateAffinePartial2D, hence the hand-rolled RANSAC) and pngjs.

History

Applied 2026-07-24 with overwrite-all + banner method: 862 entries (up from 465), build version 2026/07/24/03. Both methods independently flagged the same hand-tuned values as wrong (Ooshio 0.877 -> 0.65, Michishio, Akatsuki Kai, Kongo 0.335 -> 0.541, Shiratsuyu Kai); visual crop checks confirmed the machine values were correct, so nothing was reverted.