Rotating the tracking camera

Ador

Can I rotate the tracking camera to face downward (i mean 90 degrees kind of downward)?
i understand that I have to edit the extrinsic config, so I would change only this part:

{
  "parent": "imu1",
  "child":  "tracking",
  "T_child_wrt_parent": [0.017, 0.015, 0.013],
  "RPY_parent_to_child":  [0, 45, 90]
}

specifically this part:

"RPY_parent_to_child":  [0, 45, 90]

to:

"RPY_parent_to_child":  [0, 90, 90]

would this affect the VIO? or affect anything at all?

That should work fine, keep in mind that you should change the extrinsic with relation to imu0 as well, and that you may need to change the translation if you're not able to rotate it perfectly in place. VIO will converge internally to the actual rotation/translation values as long as they're close enough, but it can lead to errors if they're not.