[question] How can I produce a COLMAP-format dataset compatible with the original Gaussian Splatting?

[soohyoen]

Desktop (please complete the following and other pertinent information):

• OS: Ubuntu
• Python version 3.10
• Meshroom version:2023.3.0

I’m applying CCTag during SfM and would like to use the resulting SfM output with Gaussian Splatting.

The current codebase exports SfM in Nerfstudio format for Splatfacto, but I need the output converted to standard COLMAP (cameras.txt, images.txt, points3D.txt) so it can be consumed by Gaussian Splatting.

What’s the recommended approach or tooling to perform this conversion?

[natowi]

Meshroom Research has a Meshroom2ColmapSfmConvertions node:
https://github.com/meshroomHub/MeshroomResearch/tree/main/mrrs/nodes/colmap
https://github.com/meshroomHub/MeshroomResearch/tree/main Research setup required.

[beaki]

well, I had a look at this and checked out the links above.
a.) I installed the MeshroomResearch trying to follow the documentation on https://github.com/meshroomHub/MeshroomResearch. There were broken dependencies when trying to install openimageIO and its Python bindings using conda (following the link) - and that was on a newly installed and updated ubuntu 22.04. I understand that this is outside of the scope of Meshroom(Research) however this documentation does not really help.

Anyway, I worked around and got it/something installed:
b.) When running Meshroom-2025.1.0/Meshroom I could open e.g. the pipeline /MeshroomResearch/pipelines/colmap/colmap_project.mg but was told that the nodes are incompatible as they were generated with Meshroom-2023 , I got over this and then was told that there are three nodes of unknown type (PoissonMesher, MeshTransform,CopyData). I could find the *.py scripts in mrrs/nodes/colmap and it seems that the plugins or nodes were not properly installed.
(BTW C:/data/tankandtemples_mvsnet/intermediate/Francis/images * and C:/data/tankandtemples_mvsnet/intermediate/Family/images were still in the *.mg files)

c.) I had a look at the documentation https://github.com/alicevision/Meshroom/blob/develop/INSTALL_PLUGINS.md and the directory structure matches the directory structure of Meshroom-2025.1.0/plugins/mrSegmentation but not what I did find in MeshroomResearch/mrrs?

d.) I would expect to set some environment variable, like $MESHROOM_PLUGINS_PATH or $MESHROOM_NODES_PATH. The documentation talks about $MESHROOM_PLUGINS_PATH while .../MeshroomResearch/setup.py is trying to use $MESHROOM_NODES_PATH.
which one is it?

e.) just to make sure: when the plugins are installed and found I would expect to see them in the gui when right clicking the panel in the Graph Editor window at the bottom. this is the expected behavior, right?

overall, how to install those MeshroomResearch plugins?