DSVT: Dynamic Sparse Voxel Transformer with Rotated Sets
Abstract
Designing an efficient yet deployment-friendly 3D backbone to handle sparse point clouds is a fundamental problem in 3D perception. Compared with the customized sparse convolution, the attention mechanism in Transformers is more appropriate for flexibly modeling long-range relationships and is easier to be deployed in real-world applications. However, due to the sparse characteristics of point clouds, it is non-trivial to apply a standard transformer on sparse points. In this paper, we present Dynamic Sparse Voxel Transformer (DSVT), a single-stride window-based voxel Transformer backbone for outdoor 3D perception. In order to efficiently process sparse points in parallel, we propose Dynamic Sparse Window Attention, which partitions a series of local regions in each window according to its sparsity and then computes the features of all regions in a fully parallel manner. To allow the cross-set connection, we design a rotated set partitioning strategy that alternates between two partitioning configurations in consecutive self-attention layers. To support effective downsampling and better encode geometric information, we also propose an attentionstyle 3D pooling module on sparse points, which is powerful and deployment-friendly without utilizing any customized CUDA operations. Our model achieves state-of-the-art performance with a broad range of 3D perception tasks. More importantly, DSVT can be easily deployed by TensorRT with real-time inference speed (27Hz). Code will be available at https://github.com/Haiyang-W/DSVT.

Introduction
We implement DSVT and provide the results on Waymo dataset.
Usage
Installation
pip install torch_scatter==2.0.9
python projects/DSVT/setup.py develop # compile `ingroup_inds_op` cuda operation
Testing commands
In MMDetection3D's root directory, run the following command to test the model:
python tools/test.py projects/DSVT/configs/dsvt_voxel032_res-second_secfpn_8xb1-cyclic-12e_waymoD5-3d-3class.py ${CHECKPOINT_PATH}
Training commands
In MMDetection3D's root directory, run the following command to test the model:
tools/dist_train.sh projects/DSVT/configs/dsvt_voxel032_res-second_secfpn_8xb1-cyclic-12e_waymoD5-3d-3class.py 8 --sync_bn torch
Results and models
Waymo
Middle Encoder | Backbone | Load Interval | Voxel type (voxel size) | Multi-Class NMS | Multi-frames | mAP@L1 | mAPH@L1 | mAP@L2 | mAPH@L2 | Download |
---|---|---|---|---|---|---|---|---|---|---|
DSVT | ResSECOND | 5 | voxel (0.32) | ✓ | × | 75.5 | 72.4 | 69.2 | 66.3 | log |
Note:
ResSECOND
denotes the base block in SECOND has residual layers.Regrettably, we are unable to provide the pre-trained model weights due to Waymo Dataset License Agreement, so we only provide the training logs as shown above.
Citation
@inproceedings{wang2023dsvt,
title={DSVT: Dynamic Sparse Voxel Transformer with Rotated Sets},
author={Haiyang Wang, Chen Shi, Shaoshuai Shi, Meng Lei, Sen Wang, Di He, Bernt Schiele and Liwei Wang},
booktitle={CVPR},
year={2023}
}