Input Path To Absolute

Every time this node runs, it prints wahoooooo to your ComfyUI console. That's not a joke - it's literally the first line of debug output in the source, and it's there on every single execution. If you're running a Houdini Bridge workflow and the console starts yelling at you, congratulations: you found HouCuiInputPathToAbsolute (display name "Input Path To Absolute"), and it's working as intended.

Underneath the cheerleading it does one useful thing: it takes a path that's relative to ComfyUI's input/ directory and expands it to a full absolute path. The bridge speaks in relative paths between Houdini and ComfyUI so that a workflow survives being moved between machines - your Houdini scene doesn't care where ComfyUI physically lives. But plenty of nodes want a real filesystem path to do their job. This node is the adapter between those two worlds.

The two outputs

The single required input, rel_path, is the relative path you want expanded. It comes with two string outputs, and the naming is worth reading carefully:

• rel - the relative path you fed in, passed back unchanged.
• abs - the input directory joined with rel_path, e.g. ComfyUI/input/your_folder/ref.png resolved to its full absolute form.

Two things to know about abs. First, it's built with os.path.join, which means if you accidentally feed it an already-absolute path, it just hands it back - the join short-circuits. Second - and this is the one that trips people - the node does not check that the file exists. It's pure path arithmetic. Wire abs into a loader expecting an existing file and the failure happens later, at that loader, with a less obvious message. If your workflow is erroring somewhere downstream, verify the file is actually in input/ before blaming this node.

Where it fits

This is a helper inside houdini-comfyui-bridge (CapybaraCrowporation/houdini-comfyui-bridge), the community-made bridge between Houdini and ComfyUI from Rafael Drelich Valentim and Anatolii Iudanov - not a SideFX project, GPL-3.0, open-sourced at the end of 2025 and demoed at SIGGRAPH Asia 2025. It's one of a small family of path and string plumbing nodes the bridge uses for its input/output exchange: Houdini drops files into ComfyUI's input/ folder, and this node is how a graph turns those portable relative paths into absolute ones it can actually open.

Install

For the ComfyUI side, it's the usual dance:

cd ComfyUI/custom_nodes
git clone https://github.com/CapybaraCrowporation/houdini-comfyui-bridge

Restart ComfyUI (or install "houdini-comfyui-bridge" via ComfyUI Manager). No Python dependencies beyond ComfyUI itself - the custom-node half of this pack is deliberately lean. The real install weight is the Houdini plugin (OTLs added to your Houdini userdir or HOUDINI_PATH), and the docs' classic setup trap: ComfyUI Desktop uses port 8000 by default while the Houdini nodes expect 8188, so if the two won't connect, that's your first suspect.

Bottom line

If you're working the bridge, this is the node that converts the exchange-directory language into something the rest of the graph can eat. If you're not working the bridge, it's a glorified path joiner with a great sense of humor - and honestly, once you've seen wahoooooo in the logs, you'll remember this one forever.