Given a bounding box, how do I best convert the coordinates of the points within in a consistent way relative to a corner? I need just an xyz difference.
Convert point coordinates from global to box-relative
Why do you want to have them relative to a corner? Seems difficult to figure out which corner. More intuitive would be to use the center and orientation of the bounding box. Then you can transform the point into the local coordinate system and just store the xyz coordinates.
Came to the same conclusion about using the center while waiting for your reply 
Mind pointing out what function to use for the orientation transform?
We have similar transformations all throughout https://github.com/nutonomy/nuscenes-devkit/blob/master/python-sdk/nuscenes/nuscenes.py, but not one that can be directly used. The most similar one is perhaps https://github.com/nutonomy/nuscenes-devkit/blob/master/python-sdk/nuscenes/nuscenes.py#L531, but you’ll have to create the box transform yourself, as we only transform boxes to global/sensor coordinates, never points to box coordinates.
Thanks a lot, will look into it.