I’ve noticed a pretty significant performance drop in the mapper command when upgrading from COLMAP 3.11.0.dev0 to 3.13.0.dev0.

On my machine:

• 3.11.0.dev0 (commit `189478b6`) runs the Person-Hall dataset in about 7.5 minutes
• 3.13.0.dev0 (commit `c3ebe1ff`) takes about 11 minutes

Same database (from link above), same system, using default settings.

Some extra info:

• CPU: 13th Gen Intel(R) Core(TM) i9-13950HX (24 cores, 32 threads)
• System: Ubuntu-based, running COLMAP inside Docker
• Build: Used the official Dockerfile from the COLMAP repo to build both versions
• Runs: Used the same command-line settings and flags

On larger datasets (especially when using Hierarchical Mapping), the slowdown can be even worse, sometimes more than 2× slower in 3.13.

Is this a known regression? Any idea on how to debug this?
Happy to give you more info if needed.