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 <noreply@anthropic.com>
6240ed646e