[Algorithm] Support Rotated FCOS (ICCV'2019)

[liuyanyi]

Thanks for your contribution and we appreciate it a lot. The following instructions would make your pull request more healthy and more easily get feedback. If you do not understand some items, don't worry, just make the pull request and seek help from maintainers.

Motivation

#119
#114
https://github.com/jbwang1997/OBBDetection/blob/master/mmdet/models/dense_heads/fcos_head.py

Modification

• Add RotatedAnchorFreeHead
• Add RotatedFCOSHead
• Add CSLRFCOSHead
• Add RotatedIoULoss, need [Enhance] Differentiable rotated IoU mmcv#1854
• Add Doc
• Benchmark
• Publish model

Note: The result of Rotated IoU Loss is not stable, its still under tuning

BC-breaking (Optional)

Does the modification introduce changes that break the back-compatibility of the downstream repos?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. The documentation has been modified accordingly, like docstring or example tutorials.

[yangxue0827]

Mem (GB) is recorded in log.json file.
Inf Time (fps) can be test by:
python -m torch.distributed.launch --nproc_per_node=1 --master_port=29500 tools/analysis_tools/benchmark.py YOUR_CFG YOUR_MODEL --launcher pytorch

[zytx121]

Waiting for diff_iou_rotated_2d in MMCV

[codecov-commenter]

Codecov Report

Merging #223 (a9b3157) into dev (ff6d407) will decrease coverage by 1.07%.
The diff coverage is 16.11%.

@@            Coverage Diff             @@
##              dev     #223      +/-   ##
==========================================
- Coverage   31.94%   30.86%   -1.08%     
==========================================
  Files         113      119       +6     
  Lines        7394     7934     +540     
  Branches     1135     1220      +85     
==========================================
+ Hits         2362     2449      +87     
- Misses       4931     5384     +453     
  Partials      101      101              

Flag	Coverage Δ
unittests	30.84% <16.11%> (-1.08%)	⬇️

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

Impacted Files	Coverage Δ
mmrotate/models/dense_heads/rotated_fcos_head.py	10.04% <10.04%> (ø)
...rotate/models/dense_heads/csl_rotated_fcos_head.py	13.88% <13.88%> (ø)
...tate/core/bbox/coder/distance_angle_point_coder.py	21.15% <21.15%> (ø)
...ate/models/dense_heads/rotated_anchor_free_head.py	22.58% <22.58%> (ø)
mmrotate/models/losses/rotated_iou_loss.py	25.00% <25.00%> (ø)
mmrotate/models/detectors/rotated_fcos.py	83.33% <83.33%> (ø)
mmrotate/core/bbox/coder/__init__.py	100.00% <100.00%> (ø)
mmrotate/models/dense_heads/__init__.py	100.00% <100.00%> (ø)
mmrotate/models/detectors/__init__.py	100.00% <100.00%> (ø)
mmrotate/models/losses/__init__.py	100.00% <100.00%> (ø)

---

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 ff6d407...a9b3157. Read the comment docs.

[yangxue0827]

This branch has conflicts that must be resolved.

Conflicting files
docs/en/model_zoo.md
docs/zh_cn/model_zoo.md

See details below.

[yangxue0827]

LGTM
Waiting for models.

[zytx121]

Need to add metafile.yml, please refer to
https://github.com/open-mmlab/mmrotate/blob/main/configs/rotated_atss/metafile.yml