Common Configuration Files

This section describes the NeMo configuration file setup that is specific to models in the MM NeRF collection. For general information about how to set up and run experiments that is common to all NeMo models (e.g. Experiment Manager and PyTorch Lightning trainer parameters), see the Core Documentation section.

The model section of the NeMo Multimodal NeRF configuration files generally requires information about the dataset, the background and/or foreground NeRF networks, renderer and the guidance model being used. The sections on this page cover each of these in more detail.

Example configuration files for all of the NeMo Multimodal NeRF scripts can be found in the config directory of the examples {NEMO_ROOT/examples/multimodal/generative/nerf/conf}.

Trainer Configuration

Trainer configuration specifies the arguments for Pytorch Lightning Trainer Object.

trainer:
  devices: 1                     # Number of GPUs for distributed, or the list of the GPUs to use e.g. [0, 1]
  num_nodes: 1                   # Number of nodes for distributed training
  precision: 16                  # Use 16 to enable or 32 for FP32 precision
  max_steps: 10000               # Number of training steps to perform
  accelerator: gpu               # accelerator to use, only "gpu" is officially supported
  enable_checkpointing: False    # Provided by exp_manager
  logger: False                  # Provided by exp_manager
  log_every_n_steps: 1           # Interval of logging
  val_check_interval: 100        # Interval of validation
  accumulate_grad_batches: 1     # Accumulates gradients over k batches before stepping the optimizer.
  benchmark: False               # Enable the inbuilt cudnn auto-tuner to find the best algorithm to use for your hardware.
  enable_model_summary: True     # Enable or disable the model summarization

Refer to the Pytorch Lightning Trainer API section for all possible arguments

Experiment Manager Configurations

NeMo Experiment Manager provides convenient way to configure logging, saving, resuming options and more.

exp_manager:
  name: ${name}                          # The name of the experiment.
  exp_dir: /results                      # Directory of the experiment, if None, defaults to "./nemo_experiments"
  create_tensorboard_logger: False       # Whether you want exp_manger to create a TensorBoard logger
  create_wandb_logger: False             # Whether you want exp_manger to create a Wandb logger
  wandb_logger_kwargs:                   # Wandb logger arguments
    project: dreamfusion
    group: nemo-df
    name: ${name}
    resume: True
  create_checkpoint_callback: True       # Whether you want Experiment manager to create a model checkpoint callback
  checkpoint_callback_params:            # Model checkpoint callback arguments
    every_n_epochs: 0
    every_n_train_steps:
    monitor: loss
    filename: '${name}-{step}'
    save_top_k: -1
    always_save_nemo: False
  resume_if_exists: True                 # Whether this experiment is resuming from a previous run
  resume_ignore_no_checkpoint: True      # Experiment manager errors out if resume_if_exists is True and no checkpoint could be found. This behavior can be disabled, in which case exp_manager will print a message and continue without restoring, by setting resume_ignore_no_checkpoint to True

Model Configuration

Dataset Configuration

Training, validation, and test parameters are specified using the data sections in the model configuration file. Depending on the task, there may be arguments specifying the augmentations for the dataset, the image resolution, camera parameters and so on.

Any initialization parameter that is accepted for the Dataset class used in the experiment can be set in the config file. Refer to the Datasets section of the API for a list of Datasets and their respective parameters.

An example NeRF dataset configuration should look similar to the following:

model:
  data:
    train_batch_size: 1
    train_shuffle: false
    train_dataset:
      _target_: a pytorch Dataset or IterableDataset class

    val_batch_size: 1
    val_shuffle: false
    val_dataset:
      _target_: a pytorch Dataset or IterableDataset class

    test_batch_size: 1
    test_shuffle: false
    test_dataset:
      _target_: a pytorch Dataset or IterableDataset class

Model Architecture Configurations

Each configuration file should describe the model pipeline and architecture being used for the experiment.

Here is a list of modules a nerf pipeline might use:

Module	Description
`guidance`	guidance model
`nerf`	the main network for foreground density and color
`background`	a complimentary layer for background color
`material`	materials network for lightning and shading effects
`renderer`	rendering layer

Refer to DreamFusion for model specific configurations.

Optimizer Configurations

optim:
  name: adan
  lr: 5e-3
  eps: 1e-8
  weight_decay: 2e-5
  max_grad_norm: 5.0
  foreach: False

By default we use adan as the optimizer, refer to NeMo user guide for all supported optimizers.