Pass Mask

Pass Mask is a one-in, one-out passthrough for MASK data - the grayscale selection that tells ComfyUI where to inpaint, where to composite, and what a ControlNet or detailer should pay attention to. In goes a mask, out comes the identical mask. That's the entire node, and it's exactly as valuable as a well-placed junction in a big graph.

Masks are the output of one node and the input of several more than almost anything else in ComfyUI. In a typical inpainting setup your mask comes from a segmentation or edge-detection node, then feeds an inpaint conditioning node, maybe a detailer, maybe an image composite. Wire it straight and you've got a fan-out that breaks the moment you swap or bypass the mask source - suddenly every one of those downstream nodes is silently receiving nothing. A passer fixes that by giving you one stable connection point: all the consumer wires land on the passer, and you only ever reroute the single wire from your real mask source.

That's the whole reason the RvTools passer family exists. The README puts it plainly: passers were made to sit "in front of nodes that had problems getting information from bypassed nodes," and to be the second node you need to form a managed group so you can hide the mask's origin and keep the group compact. If you've ever stared at a mask-based workflow where the actual selection logic is buried three nodes back, you know exactly why a named junction helps.

The schema

• mask (MASK, required) - the mask to pass through.
• Output MASK - the same mask, unchanged.

No widgets, no Purge_VRAM toggle - that's v2 territory. This one stays pure.

Install

From ComfyUI-RvTools_v2 (r-vage). ComfyUI Manager → search "ComfyUI-RvTools_v2" → install, then restart. Or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/r-vage/ComfyUI-RvTools_v2

No model files to fetch. The pack's requirements (torch, numpy, Pillow, opencv-python, pilgram, pynvml, piexif) are standard ComfyUI companions, so installs are usually painless.

Honest caveats

The pack's README opens with a "no longer maintained" notice - it's superseded by ComfyUI_Eclipse, which absorbs most of these nodes. Still works, just frozen. And if a workflow you downloaded references the original RvTools v1 pack, that repo was pulled from GitHub and its nodes won't resolve; v2 renamed everything, which is why this node exists. For a mask used in one place, a plain wire beats a passer - reach for it when the mask fans out or the graph is getting hard to read.