Separates two confounded effects so the pending rotation decision has a number:
how much would drawing the rotation actually buy.
A per-level lookup table fitted on a screen is the most general tone model there
is -- every render level mapped to whatever capture level minimises the error,
no functional form assumed -- so whatever such a LUT cannot close is by
construction not a per-level effect. Fitting on the screen itself therefore gives
an upper bound on the tone share and a lower bound on the geometry share.
Positive control: on the main menu, where the port measures 0.06 percent of
pixels differing so geometry is essentially right, a self-fitted LUT closes
70.3 percent, from 9.26 to 2.75. The instrument can collapse a tone-dominated
residual.
Result: on the title the same self-fitted LUT closes only 32.0 percent, from
10.92 to 7.42. So at most a third of the title s disagreement is tone and at
least two thirds is spatial -- content in the wrong place, which is where the
rotation lives. The fitted LUT is generous to tone, so the geometry share is if
anything larger.
Also refutes the idea of a single transferable tone curve. Fitted on the title
and applied to the menu it closes 29.7 percent; fitted on the menu and applied to
the title it makes things 24 percent WORSE. A curve fitted on a dark flat screen
is unconstrained at the bright end -- the menu s populated range is levels 5 to
204 with few bright pixels -- and extrapolating it onto the title s planet and
wordmark actively harms. That extends the existing refutation of the single
exponent: even a full per-level LUT fails to transfer, so a consumer must not
carry a global tone correction.
Reach: two screens, one capture each, and the title pairing is the same screen
but not the same instant, so the ratio is what is claimed rather than the
absolute level. Our render draws the sweeps parent record only, so the geometry
share includes both the missing rotation and the missing leaf placement -- both
closed by the same decision.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QsEPXWVaEpyfudtR6re1Pd
f2a74efe2d