Aligning COLMAP’s Arbitrary Axes for 3D Gaussian Splatting

This video shows how to align and define a meaningful world-space coordinate system when working with COLMAP reconstructions, and how to apply that alignment in a 3D Gaussian Splatting (3DGS) pipeline.

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COLMAP outputs a mathematically valid but arbitrary coordinate frame, which can lead to confusion about orientation, scale, and camera pose when building custom viewers, renderers, or 3D reconstruction systems. In this video, we implement a deterministic axis alignment that converts COLMAP’s arbitrary frame into a semantic world coordinate system.

This alignment:
Makes camera poses and rotations interpretable
Establishes consistent world orientation (e.g. up / forward)
Prevents axis confusion when integrating COLMAP with 3DGS, NeRF, or custom engines
Simplifies debugging in Structure-from-Motion pipelines

Although demonstrated using 3D Gaussian Splatting, the method applies directly to: COLMAP, Structure-from-Motion (SfM), NeRF pipelines, and general 3D computer vision workflows.

#COLMAP #3DGaussianSplatting #3DGS #StructureFromMotion #SfM #NeRF #ComputerVision #3DReconstruction #Photogrammetry #GraphicsProgramming