SfMTransform

Description

Transform/Scale SfM using given transformation, cameras, landmarks, markers. Can be used to scale SfM to real-world size.

settings

Name

Description

Input

SfMData file

Transformation Method

Transformation method:

  • transformation: Apply a given transformation

  • auto_from_cameras: Use cameras

  • auto_from_landmarks: Use landmarks

  • from_single_camera: Use a specific camera as the origin of the coordinate system

  • from_markers: Align specific markers to custom coordinates

Transformation

Required only for ‘transformation’ and ‘from_single_camera’ methods:

  • transformation: Align [X,Y,Z] to +Y-axis, rotate around Y by R deg, scale by S; syntax: X,Y,Z;R;S

  • from_single_camera: Camera UID or image filename

Landmarks Describer Types

Image describer types used to compute the mean of the point cloud. (only for “landmarks” method). (‘sift’, ‘sift_float’, ‘sift_upright’, ‘akaze’, ‘akaze_liop’, ‘akaze_mldb’, ‘cctag3’, ‘cctag4’, ‘sift_ocv’, ‘akaze_ocv’)

Additional Scale

Additional scale to apply. (0.0-100.0, default 1.0)

Markers

Markers alignment points

Scale

Apply scale transformation.

Rotation

Apply rotation transformation.

Translation

Apply translation transformation.

Verbose Level

verbosity level (fatal, error, warning, info, debug, trace).

usage:

Details:

Transformation Method: transformation

Align [X,Y,Z] to +Y-axis, rotate around Y by R deg, scale by S; syntax: X,Y,Z;R;S (all five parameters are required) This allows the user to align and scale the point cloud by explicitly specifying the scale and “up” vector [X,Y,Z] in the point cloud’s reference system. The rotation is such that the specified [X,Y,Z] vector is aligned with [0,1,0] after the transformation.

The use-case to allow the user to derive the desired rotation by interactive manipulation of the point cloud in a 3D program (Meshlab), read off the transformation parameters and transform the point cloud. https://github.com/alicevision/AliceVision/pull/206

Transformation Method: from single camera

Sets a specific camera as origin and applies correct orientation if possible Provide Camera UID or image filename

Transformation Method: autofromlandmarks

Select Landmarks Describer Type CCTAG to apply a scale