The offline capture window is minimised but still focusable, so a scroll or key press from whoever is at the keyboard can move the camera mid-capture. That yields two screenshots of the same scene from different camera positions and an enormous, entirely spurious pixel difference - which happened during slice V4b and was correctly discarded rather than interpreted. The gate now detects camera-affecting input in the client log and exits 2, so a perturbed run cannot be mistaken for a rendering regression in either direction.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Seven of the campaign slices (V2, V4a-V4g) are renderer ports whose entire
acceptance criterion is that no pixel changed, and the existing connected
lifecycle route needs both a live ACE server and the user watching. That would
have made the campaign advance only when someone is at the keyboard.
The client renders the world from the DATs without ACDREAM_LIVE, so the existing
UI automation probe can capture a settled frame with no session created and no
ACE state to disturb. The gate wraps that: capture at the parent commit, capture
at slice HEAD, compare through the existing compare-screenshots CLI at the
project's pinned tolerance 2 / 0.001.
Determinism was measured rather than assumed, and the first measurement failed:
two captures at the same commit differed in 0.29% of pixels. The differences
were confined to the top ~180 rows, which is correct behavior rather than a bug
- the sky animates and the Dereth clock advances with wall time, so two launches
cannot agree there. Below the horizon everything was stable. Masking the top 280
rows brings two independent same-commit pairs to 15 and 17 differing pixels out
of 563,200 compared, a ~33x margin under the threshold. Masking the animated
band keeps the rest a strict identity check; relaxing the tolerance instead
would have hidden real regressions everywhere else.
Covers terrain and blending, scenery, static meshes, water, fog, and the whole
retained UI. Does not cover sky (masked), EnvCell interiors, particles, or the
paperdoll viewports, since the offline scene is a fixed outdoor view - so V4e,
V4f and V4g keep a user visual gate on top of this one.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
