H3's latent upscaler loads through the H3 module (ComfyUI's loader has no
branch for it); an upscale resizes H3's anchor pin so pass 2 stays pinned.
FunPack Sampler takes an optional wired schedule, run exactly as written.
New preset: H3 Reference to Video + second pass.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
v4's Chain Sampler became a hub: 8183 lines, roughly seventy optional
inputs, a _sample_chunk that grew six ALG arguments, and a hardcoded list of
knobs silently inert on one model family. Every technique that needed the
loop was added to it, so it collected all of them.
This one picks an algorithm and a schedule from ComfyUI's own registries --
so a sampler it gains appears here without an edit -- and runs them. Three
things stop it becoming a hub again. It never learns what a model-side
modifier is. Sampler-side ones reach it through ONE call site,
chain.process(ctx, latent), which cannot grow because the step travels in a
context object rather than in the signature. And it declares the hook points
it offers, so core hands it only what fits and it never names a modifier.
Some modifiers genuinely cannot ride on a model: they need the step index,
the schedule, or a second pass. Those attach here instead, and one asking
for a hook this sampler does not offer is absent and said so, not
half-running.
Verified against ComfyUI's own guider path with real weights: bit-identical
output. That took correcting the method, not the code -- see below.
MEASUREMENT, corrected: sampling on this Mac's MPS backend is
NONDETERMINISTIC. The same node with the same seed and the same inputs
differs run to run: 2.42 by max latent difference, 0.0008 by mean pixel gap.
Comparing by MAX said this sampler diverged from core by 14.2 and it was
about to be "fixed"; by MEAN against a measured noise floor it is 0.00000
while core against itself is 0.00183. Every comparison here now runs a
control twice first. Re-checked the Detail modifier the same way: 145x the
floor, so that claim stands.
Also matched what core's sampler actually does and this did not:
fix_empty_latent_channels using the ratios our own empty-latent node reports,
the preview and progress callback, the move back to the intermediate device,
and dropping the ratio keys so nothing rescales twice.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
