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ankitdhall / lidar_camera_calibration

ROS package to find a rigid-body transformation between a LiDAR and a camera for "LiDAR-Camera Calibration using 3D-3D Point correspondences"
http://arxiv.org/abs/1705.09785
GNU General Public License v3.0
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How to set initial rotation? #44

Closed haithamkhedr closed 5 years ago

haithamkhedr commented 6 years ago

Hello, I want to ask how do I set the initial rotation between the camera and the lidar? First of all is the rotation from cam to Lidar or from Lidar to cam? second, if I have the x-axis of the lidar pointing right, does this mean that the rot_x is 0 because the camera's x-axis is also pointing right? @karnikram @ankitdhall Thanks

blutjens commented 6 years ago

I think it's the rotation of velodyne w.r.t the camera frame.

The last line in config_file.txt defines the initial rotation.I use [1.57 -1.57 0] for the frontal setup.In the frontal setup, the front of the Velodyne VLP16 (opposite of cable) and camera point towards the marker.

The second parameter is important. It defines the rotation of the velodyne around the vertical axis. Change this, if the marker is not visible in the 'cloud' window of velodyne points. Adjust the second value in range [-3.14, 3.14]. Decreasing shifts the 'cloud' window to the left. Increasing to the right.