compatibility.md

# Compatibility with Previous Versions of MMDetection3D

This document provides detailed descriptions of the BC-breaking changes in MMDetection3D.

## MMDetection3D 0.12.0

### SUNRGBD dataset for ImVoteNet

We adopt a new pre-processing procedure for the SUNRGBD dataset in order to support ImVoteNet, which is a multi-modality method requiring both image and point cloud data. In previous versions of MMDetection3D, SUNRGBD dataset was only used for point cloud based 3D detection methods. In MMDetection3D 0.12.0, we add ImVoteNet to our model zoo, thus updating SUNRGBD correspondingly by adding image-related pre-processing steps. Specificly, we made these changes:

- Fix a bug in the image file path in meta data.
- Convert calibration matrices from double to float to avoid type mismatch in further operations.
- Add instructions in the documents on preparing image data.

Please refer to the SUNRGBD [README.md](https://github.com/open-mmlab/mmdetection3d/blob/master/data/sunrgbd/README.md) for more details.

## MMDetection3D 0.6.0

### VoteNet model structure update

In MMDetection 0.6.0, we updated the model structure of VoteNet, therefore model checkpoints generated by MMDetection < 0.6.0 should be first converted to a format compatible with the latest VoteNet structure via this [script](https://github.com/open-mmlab/mmdetection3d/blob/master/tools/model_converters/convert_votenet_checkpoints.py). For more details, please refer to the VoteNet [README.md](https://github.com/open-mmlab/mmdetection3d/tree/master/configs/votenet/README.md)