Request for a Description about the Coordinate System used

[OuYaozhong]

Hi there, @MarioBijelic

I am curious about the coordinate system of the sensors inside your dataset.

Many of the task frameworks are based on the coordinate system used in the KITTI dataset, else they will give some specific introductions about the one they used.

For KITTI dataset, it gives a figure to illustrate the coordinate system for each sensor (refer to here).

I have gone through some materials, such as paper, supplement, README.md, comment of codes and many issues of this repo, and did not find some clear instructions about the coordinate system used by SeeingThroughFog.

Would it be possible to make a statement about the coordinate system of sensors in this dataset ?

🌟Question 1: Explanation of the coordinate system of different sensors.

🌟Question 2: The length, width, and height in the annotations are calculated along with which axis ?

I think it would be helpful for the dataset user.

Thanks in advance.

Best Regards

[OuYaozhong]

The coordinate system confuses me since I try to load the data of SeeingThroughFog to the OpenPCDet framework

Since no corresponding preprocessing file for the SeeingThroughFog, I manually modified one by myself.

Then, I face a Zero Division problem during calculating the IoU.

This problem is caused by the union is calculated as zero, which is impossible, since the function has check if two boxes are overlapped in 3-D space in advance by checking if two are overlapped in BEV and overlapped in vertical.

So, I guess maybe the coordinate system used by this KITTI function and the one for SeeingThroughFog are different.

Therefore, I open this issue.

[MarioBijelic]

Hi @OuYaozhong ,
we have prepared the DatasetViewer which wraps all the transformation matrix and allows to visualise the bounding boxes together with the sensory data. This is a good starting point for finding details. The uploaded json follows the format of a tf_tree from a defines all of their child and parent nodes.
Though we also converted the calibration files here: tools/ProjectionTools/Sweden2KittiCalib/kitti_stereo_velodynehdl_calib.txt
such that Kitti data loaders etc can be easily used.
The label formatting follows the Kitti format with additional columns for more detailed 3d box poses etc. Therefore length, width and height should follow the same standard.

In regards of the IoU error and the Zero Division I don't fully understand the error. Can you post the full error message and where it happens?

Best, Mario