IAMCCS V2V Stage Switch

In a video pipeline you often want a cheap look at an intermediate - the pose map, the mask, the SAM object preview - without paying for a full final render. V2V Stage Switch is the routing node that picks which stage's output flows out of your V2V graph: the polished final result, or any of the preview/draft channels.

It's the little brother of V2V Active Backend Switch, but instead of choosing which backend runs, it chooses which output of the running pipeline you want downstream. The decision comes from stage_kind - output_stage (final) or preview_stage (drafts) - which is metadata-driven, so a planner or control bus can flip between "preview mode" and "final mode" for a whole session without you touching wires.

Inputs

• cine_linx - required; the metadata context.
• stage_kind - output_stage (default) or preview_stage.
• control_bus (optional) - can override the stage selection.
• final, draft - the final render and the draft channel, respectively.
• sam_preview, mask_preview, pose_preview, reference_preview - preview channels for SAM masks, character masks, pose maps, and reference images (all *).
• result_image, source - the final result image and the source input, for cases where you want those instead.

Outputs

• selected - whatever stage you asked for, passed through.
• report - what got selected.

Install

Ships in IAMCCS-nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/IAMCCS/IAMCCS-nodes.git

or via ComfyUI Manager (search "IAMCCS"), restart. No models, no deps.

How to think about it

If you're debugging a SCAIL or WanAnimate V2V run, preview_stage is your friend: wire a preview to the mask_preview/pose_preview channels and flip stage_kind to see exactly what the backend is seeing before you commit to a long final render. It's also how the pack's Shotboard workflows do a "review then commit" pass. The catch, same as the backend switch: every input is *, so the node won't police what you connect, and if nothing sets the stage, you get output_stage - the default is the expensive one. For a beginner, the practical move is to leave it on output_stage and only reach for preview_stage when a run looks wrong and you want to see the intermediates.