KattandClaude Opus 5.5
6240ed646e
Measured against After Effects 26.3 with the original examples/ae-spatial-tangents.jsx (three paths, ten keys, even and uneven timing): an auto-Bezier key's out tangent is (next - previous) / 6 and the in tangent its mirror, whatever the key times; an end key uses its one neighbour, (neighbour - key) / 6. EffectCraft gave end keys none and scaled middle tangents by segment length, so paths with auto-Bezier keys ran up to 28 px from AE's. All ten tangents now match; path samples are within 0.05 px. Tests that relied on end keys having no tangent now expect AE's: Spatial Bezier keeps auto keys' handles (linear keys still get a third), the motion-path handle is drawn at a sixth, and a straight loopOut path is compared within 1e-9. docs/fidelity records the method and scores. Co-Authored-By: Claude Opus 5.5 <[email protected]>
4.8 KiB
Measured keyframe fidelity
The AE 2026 replacement acceptance gates define the broader target across workflows, rendered output, work-project compatibility, performance and platforms.
The first G1 comparison measures eight original scalar Rotation cases against a live After Effects 2026 session through AEsync 2.0.4: Easy Ease, overlapping influences, asymmetric ease, overshoot, descending values, equal endpoints, 100%/100% influence and 0.1%/100% influence. Each case has 21 samples over a one-second segment. This is a scalar temporal-interpolation measurement, not an overall animation, rendering, spatial-path or application-parity score.
Reproduce
With Node.js, Rust and an installed AEsync CLI, open a scratch After Effects project and run from the EffectCraft checkout:
node examples/check-ae-ease.mjs /path/to/aesync/server/dist/cli.js
The external bridge must be answering. Signing into AEsync's embedded chat is not required. The script creates a temporary comp with an original text layer, samples its Rotation property and removes the comp on success or failure. It does not save, close or replace the current project. Run in a scratch project: creating/removing the comp still changes the dirty flag and undo history.
crates/keyframe/examples/ae_ease_samples.rs evaluates the corresponding EffectCraft keys.
examples/ae-ease-oracle.jsx records live property samples and actual ease settings after the setters.
examples/check-ae-ease.mjs checks case metadata, applied AE settings, finite values and sample times,
then compares every value with an absolute tolerance of 1e-7 degrees. A failing score exits nonzero.
Raw host observations and EffectCraft samples stay in gitignored plan/aftereffects/ref/ease/.
Only the original harness and aggregate scores in keyframe-ease.json are tracked. No Adobe artwork,
presets, screenshots, frames or implementation code are included.
Finding and validation
Measured on 5 October 2026 with After Effects 26.3x87 and AEsync 2.0.4. Before the fix,
EffectCraft normalized outgoing/incoming influence when their sum exceeded 100%. AE retains each
influence. That normalization caused maximum errors of 12.4581 degrees for 80%/80%, 8.8909 degrees
for the asymmetric case and 5.5636 degrees for the descending case. Removing normalization in both
scalar evaluation and the shared progress helper makes all eight cases pass; the largest difference
in the 168 samples is below 3e-11 degrees.
The numeric regression test checks AE-derived behavioral facts, including the formerly failing sample at 0.1 seconds (0.59243939036327 degrees; previously 1.4621885963370382). Existing linear, hold, spatial, roving and eased-range tests remain green.
Astra review also found premature Newton convergence near the flat midpoint of the 100%/100%
time curve. Its closed-form inverse and a parameter-based convergence check now have a separate
mathematical regression test at times within 1e-12 of the midpoint; that test is additional to
the 168 live AE samples.
Auto-Bezier spatial tangents
Measured on 10 October 2026 with After Effects 2026 (26.3) by running the original
examples/ae-spatial-tangents.jsx in both hosts (AfterFX.exe -r and effectcraft-cli script):
three original Position paths, ten keys, with even and uneven key timing. The script pins spatial
interpolation to auto-Bezier, since an AE preference can default new keys to linear.
AE gives each auto-Bezier key an out tangent of (next key − previous key) / 6 and the mirrored in tangent, whatever the key times; an end key uses its one neighbour, (neighbour − key) / 6. That is a Catmull-Rom spline. EffectCraft gave end keys no tangent and scaled middle keys' tangents by the lengths of their segments, so all ten tangents differed. Sampled Position along an auto-Bezier path with Easy Ease was up to 25.1 px off, and a roving path up to 27.7 px.
After the fix, all ten tangents equal AE's to the printed 0.001 px, and the two path cases are within
0.05 px over 61 samples each; what remains is the arc-length table's sub-pixel speed. The regression
test spatial_auto_bezier_tangents_follow_after_effects checks the rule on other original keys,
including a timing change. AE's output stays local; only the script and these scores are tracked.
Still unmeasured
Rendered frame comparisons now have a deterministic effectcraft_effects::fidelity::compare_frames
helper. Corpus runners can use it with locally generated host/reference frames and fail on either a
mean or maximum channel error without committing proprietary renders.
Mixed interpolation sides, non-unit durations, temporal automatic/continuous Bezier, spatial speeds, time remapping, expressions, actual rendered motion and other effects need separate corpus cases. The initial probe makes no claim about those features.