Rig extrinsics are not preserved

[cgstathis]

Using glomap 1.2.0 I specify a rig with two cameras. The second camera has:

  "cam_from_rig_rotation": [0.9999982956694152, 6.037841785203979e-05, 0.0012138303588930357, 0.001389830410931006],
  "cam_from_rig_translation": [0.0005726410946748997, 0.12696233341238145, -0.0020167230616136983]

After running glomap mapper with BundleAdjustment.optimize_rig_poses = 0 I find that the rig has been modified:

5 2 CAMERA 1 CAMERA 2 1 0.99999829566941534 6.0378417852039797e-05 0.0012138303588930359 0.0013898304109310061 0.0027715877504992143 0.61449876953090021 -0.0097609567069074712

Whereas after running colmap mapper the extrinsics remain the same.

What is the correct way to keep the rig extrinsics constant?

[lpanaf]

Hi @cgstathis, it should due to that reconstructions are normalized. Can you first visualize the reconstruction to see whether the rig looks okay? If not, there might be some errors in the code. Also, you can try to switch to colmap global_mapper, since GLOMAP is intended to migrate to COLMAP and will be supported there.

[cgstathis]

Why is the reconstruction normalized? The rig provides scale that is valuable. The reconstruction looks fine aside from the scale.

[lpanaf]

It was majorly for numerical stableness. I will check on the COLMAP and get back to you on this.