Problem: After Effects 26.2's Object Matte (pick an object with a click,
optionally a box, get a matte that follows it) had no counterpart; only
stroke-driven Roto Brush existed.
Fix: an Object Matte effect (Effect > Matte, ec.matte.objectmatte) turns
the Object Point (and optional box) on a Reference Frame into Roto Brush
strokes and segments them with Roto Brush's engine, content-keyed cache
and the model chosen in Settings > Roto Brush (MobileSAM, classical graph
cut without it). Track Object carries the matte frame by frame up to 600
frames each way; otherwise every frame is segmented on its own. Feather,
Contrast, Shift Edge, Invert and a Matte view. The engine keeps its Input
Key current so upstream edits recompute it. objectMatte.apply creates one
from agents / the CLI. Unusable prompts pass the layer through.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>