lack of map.jpg on some locations in Multitraversal data

[binbin-xu]

Thank you very much for releasing the data. I tested some data in the released multitraversal dataset. However, I found that some locations, for example location 63, do not contain map.jpg. This caused issues when loading the data using the NuScenes dataloader.

To reproduce the results, I run the following code

from nuscenes.nuscenes import NuScenes

location = 63
dataset_root = '/data/MARS/Multitraversal_2023_10_04-2024_03_08'
nusc = NuScenes(version='v1.0', dataroot=f'{dataset_root}/{location}', verbose=True)

It caused the following issue:

File "/home/bxu/.local/lib/python3.9/site-packages/nuscenes/utils/map_mask.py", line 23, in init
assert osp.exists(img_file), 'map mask {} does not exist'.format(img_file)
AssertionError: map mask /data/MARS/Multitraversal_2023_10_04-2024_03_08/63/maps/map.jpg does not exist