"It feels like it does nothing" is indistinguishable from "it does nothing",
and at 24fps a lead of 1 is 42ms - small enough to reasonably doubt. So the
shift is now provable and visible rather than taken on trust:
- shiftIndex is a pure exported function with assertions covering identity,
both directions, and clamping at each end
- the frame label always shows the mouth frame, not only when shifted, so the
number can be watched diverging from f; non-zero leads also report in ms
- the slider readout carries an explicit + sign
- the stabilised pane draws the unshifted contour as a dark-green ghost when a
lead is set, so the offset is something you can see
Also: leadIndex called opts() on every invocation - ~14 DOM reads, once per
strip thumbnail, so ~1000 per redraw at 74 frames. It reads a cached scalar now.
The "different pose" assertion checks the whole track rather than one pair:
synthetic poses hold for nine-frame beats, so a single pair can legitimately be
identical while the shift works correctly.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
MediaPipe normalises x by image WIDTH and y by image HEIGHT, so for a 1080x1920
clip one unit of x is 1080px and one unit of y is 1920px. makeXform applied a
single scale to both, stretching everything horizontally by H/W - 1.78x on this
footage. The photo underlay looked equally squashed because frameAffine divided
x by imgW, matching the equally wrong vector shapes rather than disagreeing
with them.
Fixed at ingest: landmarks convert to an isotropic space whose unit is one image
height (x *= W/H), so equal numbers mean equal pixels everywhere downstream.
Pixel mapping follows - both axes divide by imgH.
This also silently fixes head roll. fitSimilarity was fitting a rotation in a
sheared space, so the "similarity" it recovered was not one, and stabilisation
of rolled heads was subtly wrong.
selftest: a shape circular in pixel space must stay circular in raster space,
checked at 1080x1920, 1920x1080 and 640x640. Fails at ratio 1.78 without the
conversion.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Sparseness was being applied for two different reasons at once. Aesthetic
sparseness is set by the extraction rate; labour sparseness only binds on the
plate, because a human draws each one. The mouth is traced and therefore free,
and in limited animation lip sync is routinely the densest element - on 1s
while heads hold on 2s and 3s.
So: the mouth gets a key on every frame, and the frame strip is now the
editing surface for deciding which frames need their own plate drawing. All
frames start kept; delete the ones you don't want.
- strip of face-cropped thumbnails, keep/drop per frame, keyboard driven
- worksheet panel lists the drawings needed and the range each one holds
- Suggest runs error-tolerance decimation on head pose as a starting point
- export writes sparse plate keys + dense mouth keys, with a hold manifest
- smoothContours: bounded exception to "never smooth the contour", which held
only while keys were sparse enough to reject detector noise by sampling
- averages are now a RADIUS in frames: 0 is off, 1 is +-1
- GPU delegate falls back to CPU instead of failing
- #synth / #frames autorun for headless smoke tests
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Analysis half of the pipeline in docs/roto-puppet.md. Stabilises a face out
of a clip via a similarity fit on rigid landmarks, reduces the lip contour to
a fixed vertex budget, selects sparse keys on velocity minima, and previews
the result as flat indexed fills so timing can be judged without an Animator
Pro render.
- landmarks.js ordered lip/oval rings; slot position is vertex identity
- mathutil.js closed-form 2D similarity, Procrustes mean, transform smoothing
- pipeline.js stabilise -> subsample -> key-select
- raster.js indexed scanline fill, no antialiasing
- take.js take-file writer
- selftest.js 29 assertions, incl. ring simplicity at every vertex budget
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
