With Matte Only on, Cryptomatte wrote the matte into all four channels:
a premultiplied white only as opaque as the matte. After Effects'
Cryptomatte plug-in shows Matte Only as an opaque grey picture, the
matte in RGB with alpha 1 (its Matte Only render of 2026-11-05 is opaque
black where nothing is selected). The CPU effect and the GPU shader now
both give (m, m, m, 1).
Projects saved before keep their render: a hidden Matte Only In Alpha
switch (off for new instances, presets and AEP imports) is turned on by
migrate::legacy_default when an older instance is upgraded on open, and
then keeps the matte in every channel on CPU and GPU.
Tests: the CPU path for a partly covered pixel, an unselected one and
outside the aux area, in both forms; the upgrade of a saved instance;
the GPU parity test over every display with Matte Only off, on and on
with the legacy switch; the host pick tests read whole pixels.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
crypto_aux_image_with takes CryptoAux::{ColorsAndMatte, MatteOnly}, and
CryptoAux::for_display holds the rule for which displays read the ID
colours. A new GPU test checks every display x Matte Only against the CPU,
so the GPU fails the test if the shader starts reading RGB in a mode that
skips it (checked by mutation: forcing MatteOnly fails display 0).
Output is bit-identical (all displays, CPU and GPU). At 2560x1440 with 3 ranks and 2000 IDs on 8 cores the CPU effect drops from ~87-135 ms to ~44-54 ms and the GPU path's aux reduction from 38 to 8 ms for Matte, Preview and Matte Only.
AuxChannels::crypto_rank_planes resolves a layer's (ID, coverage) planes once; crypto_ranks keeps its signature on top of it. The CPU effect and the GPU effect's aux image (effectcraft_effects::crypto_aux_image, rayon) index the planes per pixel. Output is bit-identical.
3D Channel Extract, Cryptomatte, Depth Matte, Depth of Field, EXtractoR, Fog 3D,
ID Matte and IDentifier run on the GPU (fx_depth.rs / fx_depth.wgsl): aux planes
upload as a texture and are resampled onto the buffer grid with the CPU's index
arithmetic; tests compare against the CPU at 1x / 2x aux resolution, padded
buffers, half resolution and 8 / 32 bpc composites.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
