search

hku-mars / HBA

[RAL 2023] A globally consistent LiDAR map optimization module
GNU General Public License v2.0
469 stars 66 forks source link

to undistort the points or not #21

Closed CharlieV5 closed 10 months ago

CharlieV5 commented 1 year ago

Hi, I noticed that there is a variable defined as undis_t, which is used to record the time taken to remove distortion from the point cloud. However, it is not being used in practice, so undis_t is always equal to 0. I would like to ask if it is necessary to remove distortion from the point cloud at each iteration of the BA algorithm. In your algorithm, are the input pcd point clouds the original or the ones with distortion removed? I guess they are the ones with distortion removed because the output of each iteration does not change the coordinates of the points in pcd, but only updates the pose of each point cloud frame. In theory, should the original point cloud be input and the pose of each frame be iteratively optimized in the BA algorithm while removing distortion from the point cloud? After all, the pose of the point cloud frame changes after each iteration, and removing distortion actually depends on these poses.

samsdolphin commented 1 year ago

Hi @CharlieV5 , you are right, you can just delete this variable. The input pcd is already undistorted.

CharlieV5 commented 1 year ago

Hi @CharlieV5 , you are right, you can just delete this variable. The input pcd is already undistorted.

Thank you! And I want discuss the second topic, should the BA algorithm regenerate the undistorted point cloud, since the poses will be updated after each iteration and the distortion removal relies on the poses of frames?