Fix: data_path vor train and val dataloaders are the same

[nerovalerius]

The data_path for validation and train dataloader are exactly the same.

Line 10 in file: https://github.com/xinge008/Cylinder3D/blob/master/builder/data_builder.py#L10

Old:

def build(dataset_config,
          train_dataloader_config,
          val_dataloader_config,
          grid_size=[480, 360, 32]):
    data_path = train_dataloader_config["data_path"]
    train_imageset = train_dataloader_config["imageset"]
    val_imageset = val_dataloader_config["imageset"]
    train_ref = train_dataloader_config["return_ref"]
    val_ref = val_dataloader_config["return_ref"]

Possible fix:

 def build(dataset_config,
              train_dataloader_config,
              val_dataloader_config,
              grid_size=[480, 360, 32]):
        data_path_train = train_dataloader_config["data_path"]
        data_path_val = val_dataloader_config["data_path"]
        train_imageset = train_dataloader_config["imageset"]
        val_imageset = val_dataloader_config["imageset"]
        train_ref = train_dataloader_config["return_ref"]
        val_ref = val_dataloader_config["return_ref"]

        label_mapping = dataset_config["label_mapping"]

        SemKITTI = get_pc_model_class(dataset_config['pc_dataset_type'])

        nusc=None
        if "nusc" in dataset_config['pc_dataset_type']:
            from nuscenes import NuScenes
            nusc = NuScenes(version='v1.0-trainval', dataroot=data_path, verbose=True)

        train_pt_dataset = SemKITTI(data_path_train, imageset=train_imageset,
                                    return_ref=train_ref, label_mapping=label_mapping, nusc=nusc)
        val_pt_dataset = SemKITTI(data_path_val, imageset=val_imageset,
                                  return_ref=val_ref, label_mapping=label_mapping, nusc=nusc)

Best
Armin