Three parts per eye, stacked the way the mouth is - dark lash ring, sclera
inside it, iris inside that, square pupil in the iris. A blink then costs
nothing: when the lid shuts the traced ring goes flat and the lash line
collapses to a lens, which is a closed eye, drawn correctly, for free.
Lids are a FEATURE, rotoscoped like the mouth: head-local, a key on every
frame, the same contour avg knob. The iris is a PRIMITIVE - a disc at a
quantised position - and that is where the stylisation lives.
Line of sight. Gaze is the iris centre relative to the midpoint of the eye's
two corners, in units of corner distance. Both corners are in RIGID, so the
origin and the scale are immune to the performance being measured; against the
lid ring's centroid instead, every blink would drag the origin down and fake a
glance at the floor on exactly the frames where the eye is most visible. Both
eyes share one gaze - at this size the difference between the two measurements
is noise, not vergence, and independent per-eye noise reads as wall-eyed
immediately. Openness stays per-eye so a wink survives.
Gaze is then quantised to a pixel grid with a dwell, which is not a
stylisation imposed on the truth: real eyes move in saccades, and the smooth
drift left in the measurement is tracker noise plus head-compensation error.
Snapping to a grid removes the noise and recovers the saccade in one operation.
The iris is placed in the frame of the already-smoothed, already-subsampled lid
ring - slots 0 and 8 of a 16-slot ring are the corners, and subsampling to any
even budget keeps them at 0 and n/2 - so it cannot drift relative to its own
eye. Size is authored from the take mean, never remeasured per frame: a radius
that breathes by a fraction of a pixel flickers a pixel on and off around the
whole silhouette. iris anchor toggles steady/free/locked, because how much the
eye wanders turns out to be an aesthetic choice and not only a correctness one.
Blinking gets hysteresis and a dwell like the teeth, plus one knob they do not
have: blink hold. A blink is one frame at 12fps and a single frame of closed
eye reads as a dropped frame, so once the eye shuts it stays shut long enough
to be legible. Detection accuracy is not the problem; legibility is.
The pupil is a square because at three pixels a circle is a plus sign with the
corners gnawed off, and it changes shape as it moves. Drawn from a rounded
centre shared with the iris so it is exactly its nominal size on every frame.
Iris/pupil clip by colour key against the indexed buffer, the way Animator Pro
would: the lid crops the iris at extreme gaze for free, so nothing has to clamp
the gaze, which would flatten the performance at the extremes that carry it.
Which iris block belongs to which eye is RESOLVED from geometry, not declared.
A swap looks almost right - each eye still has a disc roughly where it belongs
- so it survives an eyeball and then reads as a subtly wall-eyed character
forever. Voted across every frame; the test feeds a deliberately swapped track.
Also: exposure. Aesthetic sparseness was set by the extraction rate, which made
the timing a property of a directory of PNGs - auditioning 12 against 24 meant
re-ripping and re-detecting the whole clip. It is now a render-time grid, on
1s/2s/3s/4s, so the dense track keeps everything and the audio clock is
untouched. The take format already carried an exposure field; it was never
driven. Everything rides the same grid, because a head cutting on the odd
frames while the mouth cuts on the even ones reads as two performances laid
over each other.
41 -> 91 assertions. The load-bearing new ones: the iris pairing follows a
swapped track, a blink does not fake a change of gaze, a stencilled disc cannot
spill past its clip, a 3px pupil is 3x3 at every sub-pixel centre, and exposure
never reads a pose from the future.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The test renderer turned out to be the product. Everything that decides how the
work looks - stabilisation, reduction, timing, frame removal, palette - already
happens here, and the flat indexed output already reads the way it should.
The reason to leave is in the original design's own rule: never make a timing
decision that requires a full render to evaluate. Honouring that moved every
judgement out of Animator Pro, which left the host doing nothing but writing a
file, in exchange for modal UI, minutes-long renders, one-level undo, FLX delta
invariants, a single tween state and a cel singleton.
What does NOT change is the constraint. 320x200, indexed palette, flat fills,
no antialiasing - inherited, but load-bearing rather than accidental. The
rasteriser writes palette indices and expands to RGBA only at the end precisely
so nothing can soften an edge. Modern conveniences belong in the workflow.
Adds docs/design.md: the principles, carried over without the Poco/FLX/cel
machinery, plus architecture and an honest list of what is missing - the
largest gap being that plates still have nowhere to be drawn.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
"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>
opts() declared `verts` twice - once from the lip slider and again from the
teeth slider. Duplicate keys in an object literal are silent in JS and the last
one wins, so the teeth vertex control was quietly setting the lip vertex budget
while the lip control did nothing at all.
Renamed to teethVerts, with interior.js reading it under that name.
selftest now parses the opts() literal and fails on duplicate keys, verified to
catch this exact case.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A knob wired in app.js but missing from the markup throws during wiring, aborts
the module and leaves a blank page - a symptom pointing nowhere near its cause.
It has now happened twice, so it gets a check rather than vigilance: the
selftest fetches both files and compares the id sets in each direction.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The band filled the mouth because a band is the wrong reduction: the bright
region is a blob, and reading it as "everything above a line" throws the shape
away.
Extracting a contour reintroduces the vertex-correspondence problem that made
me avoid it, but for a blob there is a way out. Radial sampling from the
centroid along N fixed directions makes vertex k always mean "the extent in
direction k": correspondence holds by construction, the count is fixed, and
temporal smoothing cannot reorder anything. It also yields a star-shaped
reduction, which suits flat colour.
Tongue rejection, which the band had no way to express:
- pixels red relative to their own brightness are dropped (teeth are neutral)
- component choice is biased toward the top of the cavity, since area alone
picks the tongue when the mouth is wide
- separate inner and outer controls: cavity erode pulls the sampled region off
the lip edge, blob grow/erode resizes the found blob
Also: a knob wired in app.js but missing from index.html threw during wiring
and left a blank page with nothing useful in the console - which is exactly
what happened to teethDwell in the previous commit. el() now names the missing
id, and window.onerror surfaces it in the status line.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Three causes, all of them mine:
Otsu always returns a split, including on a homogeneous region - given a dark
cavity with no teeth it invents a threshold and calls half the pixels bright.
The gate is now the separation between the two class means, which is the only
thing that says whether the split means anything. Coverage was the wrong
signal: it is high both when the mouth is full of teeth and when the region is
uniformly dark and Otsu has split noise.
The row scan tracked the last qualifying row anywhere rather than where the run
from the top stops, so one bright row near the bottom - a lit lower lip inside
the ring - pushed the line to full height. It now breaks at the first failing
row once the run has started.
MediaPipe's inner lip landmarks sit slightly outside the real opening, so the
sampled region included lip pixels, which are bright and sit exactly at the
boundary where they do most damage. The ring is now eroded toward its centroid
before sampling, with the amount exposed as a knob.
Adds a diagnostic panel showing the sampled crop, pixels above threshold, and
the resolved line, because tuning this from numbers alone does not tell you
whether the region being measured is even the right region.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
MediaPipe has no landmarks inside the lips, so teeth have to come from pixels.
Tracing the bright blob would give a new contour every frame with no vertex
correspondence - the exact boil docs/roto-puppet.md warns about.
So the measurement yields a scalar, not a shape: Otsu within the cavity, scanned
from the top for where the bright run stops, giving one line height per frame.
The teeth polygon is the inner lip ring clipped to that line, so the silhouette
is always the mouth's own shape and cannot disagree with the lips around it,
and the only per-frame variable is a single number that smooths trivially.
Presence gets hysteresis and minimum dwell, as plate selection does: a teeth
block blinking on and off for single frames is worse than one simply absent.
Tongue is not implemented. The same scalar approach would apply, gated on
redness rather than brightness, but it is not visible in the test footage - the
cavity reads dark with a bright upper-teeth band and nothing else.
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>
The generated face oval was never going to be good enough to draw from:
MediaPipe's face oval is the FACE boundary, cut at the hairline and excluding
hair, ears, jaw and neck, so it is an egg by construction. Segmentation would
give a real head outline but costs a 16MB model and per-frame inference for a
shape that gets replaced by a drawing anyway.
So the plate layer becomes switchable, and the useful modes are photographic:
the source frame mapped into raster space through the same transform chain the
contours go through. Registration is the whole point - the head sits still and
a drawing traced from the underlay is already aligned to the mouth. An
unregistered underlay would be decoration.
- underlay.js: pixel->raster affine (a general affine, since MediaPipe
normalises x by width and y by height), registered draw, palette posterise
- plate modes: photo / photo dim / posterized / oval / oval+photo / none, B cycles
- worksheet cells are registered composites rather than raw crops
- Save frame 4x writes a 1280x800 PNG to draw on
- selftest: FACE_OVAL simplicity, which was never asserted; a wrong ordering
there reads as a lumpy plate rather than an obvious bowtie
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>
