☁️BizyAir Fake Scribble Lines (aka scribble_hed)

The pack's own display name gives away the trick: "aka scribble_hed." This node runs HED soft-edge detection and then thins the result down until it reads like a rough hand-drawn scribble instead of a smooth gradient edge map - a way to get scribble-style ControlNet conditioning from a real photo, without hand-drawing anything.

How it works

True Scribble conditioning is meant for actual sketches - loose, rough input that leaves the model room to interpret and fill in detail creatively, which is why the wider ControlNet ecosystem treats it as "the most creative-friendly preprocessor." HED, by contrast, produces a proper soft-edge map: gradient edges with varying thickness, more forgiving than Canny but still tracking real structure closely. Fake Scribble sits between the two - it takes HED's real edge signal and processes it down until it looks and behaves like a scribble input, giving the ControlNet more latitude to reinterpret than a faithful edge map would, while still starting from an actual photo rather than something you drew.

The inputs and outputs that matter

• image - required, the source photo.
• safe (enable/disable, default enable) - the same convention used across HED-family preprocessors in this pack (see the plain HED node): clips extreme edge-strength values so compression artifacts in the source photo don't get read as real structure. Leave it on unless you deliberately want the rawest possible signal.
• resolution (default 512, 64-1024) - internal processing resolution before the result gets thinned into scribble form.

Output: a single IMAGE - the scribble-style condition map, ready to feed a scribble-capable ControlNet.

How to install it

ComfyUI Manager: search BizyAir, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/siliconflow/BizyAir

then restart. BizyAir wants an account and API key set up on first use per the README.

Common issues & troubleshooting

Output looks too close to a normal edge map. That's this node doing its job conservatively at default settings - if you specifically want the model to have more creative room, this is the preprocessor family to reach for, but expect a subtler effect than a genuinely hand-drawn scribble would give you.

You actually wanted faithful structure. Use the plain BizyAir HED Soft-Edge Lines preprocessor instead - this node is specifically for when you want the ControlNet to loosen its grip on the source image, not tighten it.

ControlNet barely reacts to the output. Confirm the ControlNet checkpoint you loaded downstream actually supports scribble conditioning - on current union models it's typically one mode among several rather than a dedicated file, so check the model card before assuming the preprocessor is at fault.