🎭 Smart USDU Mask Denoise

If the Differential Diffusion node's per-pixel mask feels like too much machinery, this is the trimmed-down version. Smart USDU Mask Denoise takes one mask and two denoise values - one for white regions, one for black - and works out the rest. The example the author ships with is the perfect mental model: mask the sky white, mask the building black, set denoise_masked to 0.5 and denoise_unmasked to 0.2, and the sky gets rebuilt while the structure only gets a light detail pass. Gray in the mask interpolates between the two.

The difference from DiffDiff is real but subtle. DiffDiff patches the model with a per-pixel threshold function and lets any mask value do its own thing. This node instead computes a single denoise value per tile from the mask intensity over that tile's region - so regions that are mostly white get sampled at ~denoise_masked, mostly-black at ~denoise_unmasked. It's a coarser tool, but it's also far easier to reason about, and it runs in a single pass without the diffdiff model patch. Reach for it when two zones is all you have.

The inputs that matter

• denoise_mask (required MASK) - the map. White = high denoise zone, black = low.
• denoise_masked (default 0.5) - denoise for white regions. The tooltip suggests "sky."
• denoise_unmasked (default 0.2) - denoise for black regions. The tooltip suggests "building."
• conditionings - per-tile CONDITIONING_LIST in row-major order; short lists reuse the last entry.
• upscale_model + the USDU core (mode_type, tile size/padding/blur, seam fix, tiled_decode) - this variant does its own pixel upscale (upscale_by default 2).

Output is a single IMAGE.

Installing it

One of the ~100 nodes in ComfyUI-ArchAi3d-Qwen by Amir Ferdos (ArchAi3d). ComfyUI Manager → search "ArchAi3d Qwen" → install → restart, or:

cd ComfyUI/custom_nodes
git clone https://github.com/amir84ferdos/ComfyUI-ArchAi3d-Qwen.git
cd ComfyUI-ArchAi3d-Qwen
pip install -r requirements.txt

Restart after. Only ComfyUI's own torch/numpy/Pillow are required here; the heavy deps in requirements.txt serve other pack nodes. Free for personal/non-commercial use; commercial work needs the author's paid license.

Common gotchas

The mask is resized to the output size, so a low-res hand-drawn mask gets blurrier edges than you expect - leave a bit of margin around boundaries. Both denoise values still get applied to every tile; the tooltip is explicit that black regions are "less denoise, but still processed." If you need a region truly untouched, you want an inpaint-style mask with a real "no touch" value, not this node. And because the per-tile denoise is computed from mask intensity, a mask with lots of gray ends up averaging out - keep your mask high-contrast if you want crisp zone behavior.