The descriptor could say where a frame's energy sat and not whether one part of
the picture was doing something different from another — and that second thing
is what "nothing to watch" means. A pattern spread evenly over the screen has no
subject precisely because every region is the same region, and `layout`
normalises that away: a uniform field and a field with a form standing in it can
come out at nearly the same distribution.
So each ninth of the frame is now characterised in its own right — how much
detail, which way it runs, how many elements — and expressed as its deviation
from the frame's average. Heterogeneity rather than level, so a brighter or
busier frame does not register as a more varied one.
It is immediately the strongest block in the descriptor, and it credits scenes
the old one was underrating:
Apollonian Gasket 0.039 -> 0.062 region 0.180
Plasma Bloom 0.053 -> 0.082 region 0.182
Moiré Grid 0.037 -> 0.047 region 0.097
Droste Feedback 0.219 -> 0.324 region 0.446
Apollonian Gasket is the interesting one. It was called out as looking good and
scoring badly, and the answer turns out to be partly that the instrument was
missing the axis it is good on rather than that beauty and variety are simply
different things. Both were true; only one of them was the instrument's fault.
The metric's own gates still hold, which is the condition for believing any of
this: recolour moves structure 0.019 while moving colour 0.723, a quarter turn
moves it 0.0000, and the same scene against itself is 0.0000 against 0.0992 for
two different scenes.
EVERY SCORE HAS MOVED. The total is a mean over six blocks now rather than five,
and the 0.04 bar was derived under the old one. It needs re-deriving from a fresh
gallery before it is used to judge anything.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A failed shader compile renders black, and black frames are identical to each
other, so every block scores 0.000 and the row reads as the least varied scene
in the library rather than as a broken one. That happened yesterday — the
subject helpers were declared above the ink they call, GLSL has no forward
declarations, the whole preamble failed to compile, and the gallery reported a
variety of exactly 0.000 with no indication anything was wrong. It is a
particularly bad failure mode for a tool whose entire job is ranking scenes by
that number.
A scene whose first frame has no luminance and no variance is now reported as
broken, with both figures and a pointer to the console, and the row is coloured
apart from the merely flat ones so it cannot be mistaken for a bad score. The
summary counts them separately.
Verified against both answers rather than only the happy one: a healthy Moiré
Grid comes back 0.0365 with no error, and a deliberately broken copy of the same
scene comes back with the diagnosis instead of a zero.
Recorded in HOWTO-variety.md alongside the other instrument traps, since the
general lesson outlives this instance — a broken render produces the most boring
possible numbers rather than an error.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
HOWTO-visualizers.md gets a scene working. Nothing said how to make one look
different from song to song, which is the thing the library is worst at and the
thing every measurement this epic has been about.
Written as evidence rather than advice: each claim carries the number behind it,
so a later change can contradict it. Several already contradict things believed
earlier in the same week.
It records the failures at least as carefully as the wins, because they were more
informative and each looked obviously right beforehand — effects as parameters
inflating a score without changing a picture, concentrating disturbance instead
of adding it, the roster-size theory that a direct sweep found to be nothing, and
reading a form as a metric rather than drawing it. It also documents what the
descriptor cannot see, since half of "why is my score low" is there: brightness,
colour, rotation, quality, and layout for anything that fills the frame.
And it is explicit about which numbers to trust. Direct render comparisons have a
noise floor of zero; aggregate ratios swing enough to have produced four
withdrawn conclusions in one epic.
Ongoing by design, with the open questions listed: coupling has never moved off
zero, fixed-geometry scenes have no known route to variety, and the 0.04 bar was
set against scores that were depressed by a measurement bug.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
