Fix: Passing sensor_t into sensor_from_rig

[nushakrishnan]

No description provided.

[sarlinpe]

Why 2? Try to avoid magic numbers or at least document them properly using a variable with unambiguous name.

[nushakrishnan]

I updating the naming for better clarity, the 2 for left camera comes from this function here where we build an initial reconstruction from a device calibration (for evaluation of each sequence).

lamaria/lamaria/utils/aria.py

Lines 31 to 74 in 6e45892

	def initialize_reconstruction_from_calibration_file(
	calibration_file: Path,
	) -> InitReconstruction:
	"""Initialize a COLMAP reconstruction from Aria calibration
	json file found on website: https://lamaria.ethz.ch/slam_datasets
	Adds a dummy camera as an IMU along with two cameras.
	Args:
	calibration_file (Path):
	Path to the Aria calibration json file
	Returns:
	InitReconstruction: The initialized COLMAP reconstruction
	"""
	reconstruction = pycolmap.Reconstruction()
	imu = pycolmap.Camera(camera_id=1, model="SIMPLE_PINHOLE", params=[0, 0, 0])
	reconstruction.add_camera(imu)
	rig = pycolmap.Rig(rig_id=1)
	ref_sensor = pycolmap.sensor_t(
	id=1, # imu is the rig
	type=pycolmap.SensorType.CAMERA,
	)
	rig.add_ref_sensor(ref_sensor)
	for i, (key, _) in enumerate(ARIA_CAMERAS):
	cam = camera_colmap_from_json(
	calibration_file=calibration_file,
	camera_label=key,
	)
	cam.camera_id = i + 2 # start from 2 since 1 is imu
	reconstruction.add_camera(cam)
	sensor = pycolmap.sensor_t(id=i + 2, type=pycolmap.SensorType.CAMERA)
	rig_from_sensor = get_t_imu_camera_from_calibration_file(
	calibration_file=calibration_file,
	camera_label=key,
	)
	sensor_from_rig = rig_from_sensor.inverse()
	rig.add_sensor(sensor, sensor_from_rig)
	reconstruction.add_rig(rig)
	return reconstruction

[sarlinpe]

This information is duplicated with a few lines below

[
                (LEFT_CAMERA_STREAM_LABEL, 2),
                (RIGHT_CAMERA_STREAM_LABEL, 3),
]

[sarlinpe]

This won't work if the reconstruction already has images, cameras, or rigs, should we assert this? or make this code more generic?

[nushakrishnan]

It is a hidden function that we don't want to expose. We only use it to add estimate poses to an already initialized reconstruction:

lamaria/lamaria/structs/trajectory.py

Lines 78 to 91 in c3d467b

	def add_estimate_poses_to_reconstruction(
	self,
	reconstruction: pycolmap.Reconstruction,
	timestamp_to_images: dict,
	) -> pycolmap.Reconstruction:
	"""
	Adds estimate poses as frames to input reconstruction.
	"""
	self._ensure_loaded()
	reconstruction = self._add_images_to_reconstruction(
	reconstruction, timestamp_to_images
	)
	return reconstruction

[nushakrishnan]

Whereas the more general function is to initialize the reconstruction with a calibration file (pinhole/Aria camera):

lamaria/lamaria/utils/aria.py

Line 31 in c3d467b

def initialize_reconstruction_from_calibration_file(