[Feature] SemanticKITTI Dataset

[junhaozhang98]

1)ini add
2)semantickitti_datset
3)test data

[CLAassistant]

All committers have signed the CLA.

[ZwwWayne]

Please sign CLA and fix CI.

[ZwwWayne]

tests/data/semantickitti/sequences/00/velodyne/000000.bin is too large. We need to make the uploaded file as small as possible to reduce the repo size for the convenience of download.

[codecov]

Codecov Report

Merging #287 (ffb082c) into master (87b05ba) will increase coverage by 0.13%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #287      +/-   ##
==========================================
+ Coverage   50.09%   50.22%   +0.13%     
==========================================
  Files         172      173       +1     
  Lines       11572    11587      +15     
  Branches     1802     1803       +1     
==========================================
+ Hits         5797     5820      +23     
+ Misses       5409     5406       -3     
+ Partials      366      361       -5     

Flag	Coverage Δ
unittests	50.22% <100.00%> (+0.13%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
mmdet3d/datasets/__init__.py	100.00% <100.00%> (ø)
mmdet3d/datasets/pipelines/loading.py	74.16% <100.00%> (+1.78%)	⬆️
mmdet3d/datasets/semantickitti_dataset.py	100.00% <100.00%> (ø)
mmdet3d/datasets/pipelines/transforms_3d.py	84.03% <0.00%> (+1.12%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 87b05ba...78ae4e3. Read the comment docs.

[OpenMMLab-Assistant-007]

Hi!
@junhaozhang98
First of all, we want to express our gratitude for your significant PR in the OpenMMLab project. Your contribution is highly appreciated, and we are grateful for your efforts in helping improve this open-source project during your personal time. We believe that many developers will benefit from your PR.

We would also like to invite you to join our Special Interest Group (SIG) private channel on Discord, where you can share your experiences, ideas, and build connections with like-minded peers. To join the SIG channel, simply message moderator— OpenMMLab on Discord or briefly share your open-source contributions in the #introductions channel and we will assist you. Look forward to seeing you there! Join us ：https://discord.gg/UjgXkPWNqA

If you have WeChat account，welcome to join our community on WeChat. You can add our assistant ：openmmlabwx. Please add "mmsig + Github ID" as a remark when adding friends：）
Thank you again for your contribution❤