Train RandLANet from Readme does not seem to work

[nikste]

Checklist

• I have searched for similar issues.
• I have tested with the latest development wheel.
• I have checked the release documentation and the latest documentation (for main branch).

Describe the issue

trying the code from the readme:

import ml3d
from ml3d.torch import RandLANet, SemanticSegmentation

# use a cache for storing the results of the preprocessing (default path is './logs/cache')
dataset = ml3d.datasets.SemanticKITTI(dataset_path='/path/to/SemanticKITTI/', use_cache=True)

# create the model with random initialization.
model = RandLANet()

pipeline = SemanticSegmentation(model=model, dataset=dataset, max_epoch=100)

# prints training progress in the console.
pipeline.run_train()

(after adding the imports, would be amazing if they were also included in the example code)
results in:

Traceback (most recent call last):
  File "open3d-ml/train_semseg_pipeline.py", line 15, in <module>
    pipeline.run_train()
  File "open3d-ml/ml3d/torch/pipelines/semantic_segmentation.py", line 376, in run_train
    self.optimizer, self.scheduler = model.get_optimizer(cfg)
  File "open3d-ml/ml3d/torch/models/randlanet.py", line 354, in get_optimizer
    **cfg_pipeline.optimizer)
  File "open3d-ml/ml3d/utils/config.py", line 244, in __getattr__
    return getattr(self._cfg_dict, name)
  File "open3d-ml/ml3d/utils/config.py", line 27, in __getattr__
    raise ex
AttributeError: 'ConfigDict' object has no attribute 'optimizer'

Am I doing something wrong here?

Steps to reproduce the bug

see above

Error message

Traceback (most recent call last):
  File "open3d-ml/train_semseg_pipeline.py", line 15, in <module>
    pipeline.run_train()
  File "open3d-ml/ml3d/torch/pipelines/semantic_segmentation.py", line 376, in run_train
    self.optimizer, self.scheduler = model.get_optimizer(cfg)
  File "open3d-ml/ml3d/torch/models/randlanet.py", line 354, in get_optimizer
    **cfg_pipeline.optimizer)
  File "open3d-ml/ml3d/utils/config.py", line 244, in __getattr__
    return getattr(self._cfg_dict, name)
  File "open3d-ml/ml3d/utils/config.py", line 27, in __getattr__
    raise ex
AttributeError: 'ConfigDict' object has no attribute 'optimizer'

Expected behavior

No response

Open3D, Python and System information

- Operating system: ubuntu

Additional information

No response

[nikste]

Changing the script to the following does seem to run through:

from open3d import _ml3d

import ml3d
from ml3d.torch import RandLANet, SemanticSegmentation

dataset_path =  '/path/to/SemanticKITTI/'
cfg_path = "ml3d/configs/randlanet_semantickitti.yml"

cfg = _ml3d.utils.Config.load_from_file(cfg_path)
dataset = ml3d.datasets.SemanticKITTI(dataset_path=dataset_path, use_cache=True)

# create the model with random initialization.
model = RandLANet(**cfg.model)

pipeline = SemanticSegmentation(model=model, dataset=dataset,   **cfg.pipeline) #max_epoch=100,

# prints training progress in the console.
pipeline.run_train()