How to obtain voxel labels?

Hi,

Thanks for releasing code! I have a question about how to obtain voxel labels? In the code, you only compute voxel coordinates and features. How to compute voxel label?

<img width="417" alt="image" src="https://github.com/dvlab-research/PointGroup/assets/142866313/01736e45-3c7c-44e7-ad8c-ebd640ff9629">

