MiniMax H3 Lazy Motion Scene Preview

When your lazy motion reference is a long file, it's easy to lose track of which 24 fps slice each scene is actually going to feed on. This node exists to answer exactly that question: it decodes the precise motion-reference window for one selected Plan scene and shows it to you, before you spend a sample finding out you pointed scene 7 at the wrong ten seconds of footage.

What it does

Connect the preview_source output from Tagged Motion Ref Path, pick a scene (the numeric arrows double as a scene counter), and the node decodes that scene's exact motion-reference window at 24 fps. You get:

• scene_video - the decoded frames for the selected scene.
• scene_audio - audio from the identical window (or blocked when unavailable).
• status - selected scene, timeline rule, decoded frame count, and dimensions.

The one thing it won't do is feed anything back into generation. It's an inspection branch only - the reference fingerprint for Plan comes from the real motion-reference chain, not from this node. Wire the optional plan input (the same Loop Plan used for generation) so the node can resolve the scene windows; without a Plan, both media outputs stay blocked and you get nothing but a status string. That's by design, not a bug - it refuses to guess.

Where it sits

This pairs naturally with the lazy motion-reference flow from the Lazy Motion AV Loader / Source Timeline. Your Plan defines scene starts and how each scene maps onto the source; this preview just makes the mapping visible. Review scene 3's window before queueing, confirm the motion you expect is in the frame, and adjust skip_first_frames upstream if the window drifted off-target. It's cheap - a single decoded window, not a full-file decode - so it's the right thing to leave hanging off your motion branch permanently.

Install and gotchas

cd ComfyUI/custom_nodes
git clone https://github.com/ethanfel/ComfyUI-MiniMaxH3-Contex-Loop.git

Restart, or install via ComfyUI Manager under "MiniMax H3 Contex Loop". No pip dependencies; a current ComfyUI with native Add Guide for MiniMax H3 (PR #15439) is expected, and ffmpeg on PATH is preferred. Models aren't bundled - check the MiniMax H3 Community License (local weights restricted in US/EU/UK/Korea) before committing.

The trap to avoid: don't wire this node's outputs into your generation path to "preview what's going in." It's a pure inspection node. The motion that actually reaches H3 comes from the reference chain; this node just lets you verify it without a render.