Face Only Mode Switch (Stand-In)

Looked at on its own, this node does nothing: one boolean widget in, the same boolean out under a new name. If that's all it did, it wouldn't be worth an article. What it actually solves is a coordination problem, and it's worth understanding why it exists before you decide you don't need it.

face_only_mode shows up as its own local widget on three other nodes in this pack - ApplyFaceProcessor, VideoInputPreprocessor, and VideoBackgroundRestorer - and their defaults don't agree with each other. It's false on ApplyFaceProcessor and true on both video nodes. Set each one by hand and it's easy to end up with a pipeline where your face-prep step assumes one thing and your generation or restoration step assumes another, and now your composite looks subtly wrong with nothing in the graph obviously telling you why.

How it works

Wire this node's output to the face_only_mode input on every node you want kept in sync (right-click each node → Convert Widget to Input, then connect). Flip the one switch, and everything downstream that's listening updates together. It's the same pattern rgthree-style "context" nodes use for keeping settings consistent across a big graph, just scoped to this one flag.

As for what the flag itself changes: as the name and the existence of a dedicated VideoBackgroundRestorer node both suggest, it toggles between constraining Stand-In's identity edit to a tight face crop - leaving hair, shoulders, and background as untouched as possible so the restorer has a clean original to composite back onto - versus letting the identity conditioning influence more of the frame.

The input and output that matter

• enabled (boolean, default false) - the only setting. There's nothing else to configure.
• face_only_mode (boolean) - the output. Feed this into every face_only_mode input across the pack that needs to agree.

How to install it

cd ComfyUI/custom_nodes
git clone https://github.com/WeChatCV/Stand-In_Preprocessor_ComfyUI.git
cd Stand-In_Preprocessor_ComfyUI
pip install -r requirements.txt

Restart ComfyUI, or grab it through ComfyUI Manager by searching "Stand-In Official Preprocessor ComfyUI Nodes."

Common issues & troubleshooting

Nothing changes when you flip it. This node genuinely can't cause a bug on its own - it just relays a boolean. If flipping the switch doesn't change your output, the fault is downstream: check that you actually converted face_only_mode to an input on each node and connected it, rather than leaving that node's own local widget in charge. ComfyUI won't warn you a node is still using its own toggle instead of listening to this one - that's the one real trap here, and it's easy to think you fixed a setting when you only fixed it on some of the nodes.

You're not sure you need this node at all. If you're only running one or two Stand-In nodes in a graph, you probably don't - just set face_only_mode directly on the node that has it. This switch earns its keep once you've got three or more of them and want to stop hunting for mismatched defaults.