PreviewDetailerHookProvider

Detailing a lot of regions is slow, and staring at a spinner wondering if it's working is worse. This node fixes that: it produces a hook you plug into a detailer so you get a live preview each time a region finishes and gets pasted back onto the image. Instead of waiting for the entire pass to complete, you watch the picture improve incrementally. For big jobs - Make Tile SEGS tiled upscales, a frame with dozens of detections - that running preview is the difference between "is this hung?" and "oh good, it's on tile 14 of 30."

If "hook" is unfamiliar in Impact Pack terms: a hook is a small behavior object you attach to a detailer or upscaler to change what it does at each step. This one's behavior is "show me a preview after each paste."

How it works

It outputs a DETAILER_HOOK (and an UPSCALER_HOOK) that the detailer calls as it composites each refined region back onto the original image. Every time a region is pasted, the hook emits a preview. Two consequences worth internalizing. First, because it fires on paste-back, it has no effect on nodes like SEGSDetailer that refine crops without compositing them onto the original - there's no paste event to hook, so you'll see nothing. Second, the quality input is the JPEG quality of those previews, so it's a size-vs-clarity trade for the preview images, not a knob that touches your actual output. Your final image quality is unaffected either way.

The input and outputs

• quality (INT, default 95, range 20–100) - JPEG quality of the incremental previews. Lower it if the previews are heavy; it does not change the rendered result.

Outputs are DETAILER_HOOK and UPSCALER_HOOK - wire the matching one into the detailer_hook (or upscaler hook) input of the node doing the work. Chain it with other hooks via DetailerHookCombine if you want previews and some other hook behavior at once.

How to install it

Bundled in Impact Pack. ComfyUI Manager: search ComfyUI Impact Pack, Install, restart. Or:

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

then pip install -r requirements.txt in ComfyUI's Python env (portable: python_embeded\python.exe -m pip ...), restart. Pack's by ltdrdata, the ComfyUI-Manager author - safe and mainstream. The hook itself needs no models.

Common issues & troubleshooting

The number-one "it's not working" report is using it with SEGSDetailer and seeing no previews - that's expected, because SEGSDetailer doesn't paste back onto the original, so there's nothing for this paste-time hook to fire on. Use it with the detailers that composite (the Detailer/FaceDetailer family) and previews appear. If you want previews of the refined crops before pasting, that's SEGSPreview's job, not this. Also, don't expect the quality slider to sharpen your output - it only governs the preview JPEGs; if your final faces look soft, that's a detailer setting (denoise, guide size, steps), nothing to do with this hook.