Filename Construct

Straight up: this node lives in the pack's DEPRECATED category, and the class carries a DEPRECATED = True flag. The author's own pack has moved on to a FilenameGenerator set, and the README points everyone to ComfyUI_Eclipse as the current home of these ideas. So if you're wiring a fresh workflow, you're probably better served elsewhere. But if you've loaded a workflow that demands this node, it still runs, and here's what it does.

What it actually does

Filename Construct is a batch filename builder aimed at video clip workflows - the "save N clips, then join them" kind. It takes a folder path, a filename_prefix (default "vc"), a starting filename_suffix counter, a number_padding width (default 4, so 0001), and a file_extension (default .mp4). Then it generates ten filenames: five normal clips (vc_0001.mp4 … vc_0005.mp4) and five "join" variants (vc_join_0001.mp4 … vc_join_0005.mp4), all baked onto the path with backslashes. It also stuffs three other widgets into the output: mask_frames_last, mask_frames_first, and frame_load_cap.

That last part matters, because the single pipe output isn't a typical RvTools model/clip/vae pipe - it's a raw Python list, ordered as [mask_frames_last, mask_frames_first, frame_load_cap, clip1…clip5, join1…join5]. It's meant to feed this pack's older video-clip handling nodes that expect exactly that 13-element layout. If you plug it into something expecting a different pipe shape, you'll get confusion, not a clear error.

The inputs that matter

• path - the target folder. The node concatenates with \ and makes no effort to fix your separator, so use a Windows-style path or don't blame it when the file lands oddly.
• filename_prefix / filename_suffix / number_padding - the name, the starting counter, and how many digits to pad to.
• file_extension - defaults to .mp4, which tells you the intended audience.
• mask_frames_last / mask_frames_first / frame_load_cap - video frame-trimming values, passed through into the pipe untouched. If you're not doing masked video work, the defaults (0, 10, 81) are fine to leave alone.

Output: one pipe - the 13-element list described above.

Install

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

Or search "ComfyUI-RvTools_v2" in ComfyUI Manager. No model downloads; deps are the pack's standard torch/numpy/Pillow/opencv-python/pilgram.

Should you use it?

Only if a legacy workflow makes you. The filename it builds uses backslash paths, a $-free but Windows-flavored layout, and hardcodes a five-plus-five clip structure - all of which are opinions from an older era of this author's tooling. On top of that, the whole pack is unmaintained, and the original RvTools repo was pulled from GitHub in early 2025 (there's an r/comfyui thread of people trading installs of it after the takedown). For new work, look at the pack's own FilenameGenerator nodes or Eclipse. For rescuing an existing workflow, this still computes, and now you know exactly what the list it hands back contains.