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>