Livox Avia, + Depth cameras and organized point clouds.

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Livox Avia, + Depth cameras and organized point clouds.

FPSychoric
Hi, I'm interested in get organized/structured pointclouds to as the unorganized/unstructured pointclouds are problematic for reconstruction as you need make normals etc

I have a livox Avia with possibility of  Realsenses R200 and  D435i or OAK-D and OAK-D Pro W Dev(150FOV global shutter), but actually installed D435i, probably is better make it work first time with this one.

If it is possible I would like can get organized pointclouds with the lidar and the camera, and colourized with the RGB camera stream.

Right now, I have everything synched by nPTP, I have the camera/ lidar extrinsics in a 4x4 matrix that I don't know convert to TF without help as I don't know maths or programming, I have the internal Livox IMU delay, but I can get the d435 if needed, (maybe fuse them is better?). I can get external odometry synched and quite robust but without loop closure. I can get unorganized coloured pointcloud2 from other node (the same gives the odometry).
I can add RTK via Ublox M8T+RTKlib or PPK if it is needed.

With this info can you tell me if I can get organized pointclouds? Maybe passing laser cloud to depth with rtabmap pointcloud to depth node and reproject it? I tried but I got nothing, probably I do something wrong as I didn't read how to use that node yet.

Thanks, if you have a global idea about how do it is enough, I will find how to do it or ask if I get stuck, I don't want take you many time.

In other post here about Livox  Avia you asked  to the person how he got the Avia/Camera extrinsics in a 4x4 matrix but you didn't get answer , the way to do it is with this
https://github.com/hku-mars/livox_camera_calib

They have other node to get the IMU extrinsics and delay.

I hope that help you

Reply | Threaded
Open this post in threaded view
|

Re: Livox Avia, + Depth cameras and organized point clouds.

matlabbe
Administrator
I assume your 4x4 matrix looks like
[R00 R01 R02 Tx]
[R10 R11 R12 Ty]
[R20 R21 R22 Tz]
[0   0   0   1]
You can find some examples on internet on how to convert the rotation matrix (R3x3) to a Quaternion or Euler angles. You can then use a static_transform_publisher to publish the transform (note that you have already the translation part Tx-Ty-Tz).

What do you mean by "organized pointclouds"? do you want an organized 3D map organized (which I am not sure it is possible) or that for each RGB frame, you generate the corresponding Depth image from the lidar data?

There are some options with rtabmap to color a lidar point cloud or to generate depth image from lidar registered to RGB camera.

cheers,
Mathieu
Reply | Threaded
Open this post in threaded view
|

Re: Livox Avia, + Depth cameras and organized point clouds.

FPSychoric
Hi thanks, I will find out that part of the matrix, I should know it already.

By organized pointclouds I mean the same data/pointcloud type that the terrestrial survey scanners make, I think is they give a depth matched with pixels and use .las files often, have a different structure of data than the pointclouds tha livox or Velodine gives.
I think is the same type of pointcloud that the R200 and kinect made, maybe correspond with the called registered in Rtabmap

Thanks!