Fake Scribble Preprocessor Provider (SEGS)

This node only makes sense if you're already living in the Impact Pack's SEGS world, so let's start there. SEGS is Impact Pack's format for a batch of detected regions - faces, hands, whatever a detector found - and the detailer nodes resample each region for extra quality. Impact Pack lets you apply a ControlNet to those regions individually, and to do that it needs a preprocessor packaged in a way the SEGS machinery understands. That's what this node hands you: a scribble preprocessor, wrapped as a SEGS_PREPROCESSOR.

Fake Scribble itself is a preprocessor from the ControlNet auxiliary set. It runs edge detection (HED under the hood) and then thins the result into loose, sketch-like lines - a "fake" hand-drawn scribble derived from a real image. It's more forgiving than hard Canny edges: good when you want structural guidance without pinning every contour exactly. See the ControlNet notes in our knowledge base for how scribble and soft-edge conditioning differ.

How it works

Crucially, this node doesn't process an image when you run it. It's a provider - it outputs a SEGS_PREPROCESSOR object describing "use fake scribble." You plug that into an Impact Pack node that applies ControlNet to SEGS, and the preprocessing then happens per detected region at execution time, feeding a scribble ControlNet that steers each region's refinement. It's the SEGS-native way to say "control these regions with a scribble hint" instead of running one preprocessor over the whole frame.

The inputs and outputs

• safe (BOOLEAN, default true) - the standard safe-mode toggle from the ControlNet aux preprocessors. It clamps the preprocessor's output to a conservative range to avoid artifacts. Leave it on unless you have a specific reason not to.
• Output is a single SEGS_PREPROCESSOR, wired into Impact Pack's Apply ControlNet (SEGS)-style node.

One input, one output. The node is deliberately thin - the real work happens where you apply it.

How to install it

ComfyUI Manager: Install Custom Nodes → search ComfyUI Inspire Pack → install → restart. Or clone:

cd ComfyUI/custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Inspire-Pack

This node has two extra dependencies you can't skip. It needs the Impact Pack (also Dr.Lt.Data's) for the SEGS system it plugs into, and Fannovel16's comfyui_controlnet_aux for the actual scribble preprocessor - the Inspire README credits that pack as where the preprocessor code comes from. Install both through Manager the same way, and restart. You'll also need a scribble ControlNet model for your base architecture on the applying node.

Common issues

If the node loads but does nothing at generation time, the usual cause is a missing dependency - comfyui_controlnet_aux not installed, so there's no preprocessor to run, or Impact Pack absent so there's no SEGS node to apply it in. Second, this is a provider; wiring its output into anything other than a SEGS ControlNet-apply node won't work, because nothing else knows what a SEGS_PREPROCESSOR is. And match the ControlNet model to your base model - a SD1.5 scribble ControlNet on an SDXL or Flux workflow will either error or quietly do nothing.