Same capture, counts only. Title's first drawn element is frame 706; the
sweep is first submitted at 746 and first ON SCREEN at 747, so +41 frames.
For scale, the plate's declared t=236 is frame ~942 at 1 unit/present --
195 frames after the sweep is already visible geometrically.
Named rather than folded in: that comparison assumes the title's first
drawn frame is its t=0 and that its clock runs at 1 unit/present. The 41 is
a raw frame count and carries neither.
What it settles: POSITION does not gate the sweep late. So if a human sees
it start when the plate appears, the gate cannot be where the quad is -- it
has to be how opaque it is. That puts the whole of F6 on unit 2, which is
amber: does the parent's alpha multiply into the leaf? The parent ramps
0->255 across t=70..100, so if it multiplies the sweep is invisible until
~70 and dim to 100 (a real early gate); if it does not, the sweep is fully
lit from +41 frames and the human's report has no mechanism yet.
The disagreement has narrowed usefully: before this unit "starts when the
plate appears" had two candidate mechanisms, position or alpha. Position is
now excluded by measurement.
Refutes my own unit 1 framing. I wrote that a quad can be "fully opaque and
entirely off-screen" and offered the travel as the likely explanation. It
is not -- the sweep is on screen at +41 frames, nowhere near the plate. The
travel explanation is dead, and I record it because I proposed it and it
steered the port's reading of their own renderer.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Jc4pciRArGHfxGGhEbwp5t
a30761f128