Postshot Export (mtb)

This is the most niche node in the whole pack, and its default value gives away the whole story before you even read a description: postshot_cli defaults to C:/Program Files/Jawset Postshot/bin/postshot-cli.exe. Postshot is a real, external desktop application from Jawset for training 3D Gaussian splats (and NeRFs) out of a set of photos or a video - it's used in actual AI-virtual-production pipelines where people bring diffusion-generated frames into a tracked 3D scene, and it ships an Unreal Engine plugin for exactly that. This node doesn't do any of that training itself. It's a thin wrapper that shells out to Postshot's own command-line tool to trigger an export of an already-trained Postshot project into a .ply file - the standard interchange format for point clouds and Gaussian splats.

If you don't already have Postshot installed and a trained project on disk, this node has nothing to do. It's not a splat generator; it's the last mile of a pipeline that starts entirely outside ComfyUI.

Inputs and outputs that matter

• project_file - the path to an existing Postshot project (built inside Postshot itself, from your photos or video).
• export_splat_ply (default output.ply) - the output filename for the exported point cloud.
• postshot_cli (default the Windows Program Files path above) - the path to Postshot's own postshot-cli.exe. This is your real signal that this node is Windows-only unless you manually point it at a different install location.

Output is a single STRING - exported_ply_path, the path to the file it just wrote. It's flagged as an output node, so running it produces the exported .ply on disk as a side effect.

Installing it

You need two separate things, and only one of them is a ComfyUI node install:

1. MTB Nodes - via ComfyUI Manager (search "MTB Nodes"), or manually: cd ComfyUI/custom_nodes && git clone https://github.com/melMass/comfy_mtb, restart, running pip install -r requirements.txt first if you cloned by hand.
2. Postshot itself - a separate, non-ComfyUI, Windows desktop application from Jawset. This node has no ability to install or configure Postshot for you; it just calls its CLI once Postshot is already set up and you've already trained a project inside it.

Common issues & troubleshooting

It fails immediately, path not found. Almost certainly postshot_cli doesn't point at where Postshot is actually installed on your machine - the default is a specific Windows path that only matches a standard install location. Update it to wherever postshot-cli.exe actually lives.

Running on Linux or macOS. The default path is a Windows .exe - this node was built assuming a Windows Postshot install. If Postshot doesn't run on your platform at all, this node has nothing to call.

The export runs but the .ply looks wrong or empty. That's a Postshot-side problem, not something this node can diagnose - check the project inside Postshot's own UI first to confirm training actually completed and the project itself is valid before assuming the export step is at fault.

Some mtb nodes fail to load at startup, but this one specifically doesn't show up. Given how narrow its use case is, check the console for [comfy_mtb] STATUS and http://127.0.0.1:8188/mtb - it's a plausible candidate for one of the pack's less commonly exercised nodes.