pytorch3d/projects/nerf/train_nerf.py
Jeremy Reizenstein f00ef66727 NeRF training: avoid caching unused visualization data.
Summary: If we are not visualizing the training with visdom, then there are a couple of outputs of the coarse rendering step which are not small and are returned by the renderer but never used. We don't need to bother transferring them to the CPU.

Reviewed By: nikhilaravi

Differential Revision: D28939958

fbshipit-source-id: 7e0d6681d6524f7fb57b6b20164580006120de80
2021-06-08 04:35:22 -07:00

269 lines
9.1 KiB
Python

#!/usr/bin/env python3
# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
import collections
import os
import pickle
import warnings
import hydra
import numpy as np
import torch
from nerf.dataset import get_nerf_datasets, trivial_collate
from nerf.nerf_renderer import RadianceFieldRenderer, visualize_nerf_outputs
from nerf.stats import Stats
from omegaconf import DictConfig
from visdom import Visdom
CONFIG_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), "configs")
@hydra.main(config_path=CONFIG_DIR, config_name="lego")
def main(cfg: DictConfig):
# Set the relevant seeds for reproducibility.
np.random.seed(cfg.seed)
torch.manual_seed(cfg.seed)
# Device on which to run.
if torch.cuda.is_available():
device = "cuda"
else:
warnings.warn(
"Please note that although executing on CPU is supported,"
+ "the training is unlikely to finish in reasonable time."
)
device = "cpu"
# Initialize the Radiance Field model.
model = RadianceFieldRenderer(
image_size=cfg.data.image_size,
n_pts_per_ray=cfg.raysampler.n_pts_per_ray,
n_pts_per_ray_fine=cfg.raysampler.n_pts_per_ray,
n_rays_per_image=cfg.raysampler.n_rays_per_image,
min_depth=cfg.raysampler.min_depth,
max_depth=cfg.raysampler.max_depth,
stratified=cfg.raysampler.stratified,
stratified_test=cfg.raysampler.stratified_test,
chunk_size_test=cfg.raysampler.chunk_size_test,
n_harmonic_functions_xyz=cfg.implicit_function.n_harmonic_functions_xyz,
n_harmonic_functions_dir=cfg.implicit_function.n_harmonic_functions_dir,
n_hidden_neurons_xyz=cfg.implicit_function.n_hidden_neurons_xyz,
n_hidden_neurons_dir=cfg.implicit_function.n_hidden_neurons_dir,
n_layers_xyz=cfg.implicit_function.n_layers_xyz,
density_noise_std=cfg.implicit_function.density_noise_std,
visualization=cfg.visualization.visdom,
)
# Move the model to the relevant device.
model.to(device)
# Init stats to None before loading.
stats = None
optimizer_state_dict = None
start_epoch = 0
checkpoint_path = os.path.join(hydra.utils.get_original_cwd(), cfg.checkpoint_path)
if len(cfg.checkpoint_path) > 0:
# Make the root of the experiment directory.
checkpoint_dir = os.path.split(checkpoint_path)[0]
os.makedirs(checkpoint_dir, exist_ok=True)
# Resume training if requested.
if cfg.resume and os.path.isfile(checkpoint_path):
print(f"Resuming from checkpoint {checkpoint_path}.")
loaded_data = torch.load(checkpoint_path)
model.load_state_dict(loaded_data["model"])
stats = pickle.loads(loaded_data["stats"])
print(f" => resuming from epoch {stats.epoch}.")
optimizer_state_dict = loaded_data["optimizer"]
start_epoch = stats.epoch
# Initialize the optimizer.
optimizer = torch.optim.Adam(
model.parameters(),
lr=cfg.optimizer.lr,
)
# Load the optimizer state dict in case we are resuming.
if optimizer_state_dict is not None:
optimizer.load_state_dict(optimizer_state_dict)
optimizer.last_epoch = start_epoch
# Init the stats object.
if stats is None:
stats = Stats(
["loss", "mse_coarse", "mse_fine", "psnr_coarse", "psnr_fine", "sec/it"],
)
# Learning rate scheduler setup.
# Following the original code, we use exponential decay of the
# learning rate: current_lr = base_lr * gamma ** (epoch / step_size)
def lr_lambda(epoch):
return cfg.optimizer.lr_scheduler_gamma ** (
epoch / cfg.optimizer.lr_scheduler_step_size
)
# The learning rate scheduling is implemented with LambdaLR PyTorch scheduler.
lr_scheduler = torch.optim.lr_scheduler.LambdaLR(
optimizer, lr_lambda, last_epoch=start_epoch - 1, verbose=False
)
# Initialize the cache for storing variables needed for visualization.
visuals_cache = collections.deque(maxlen=cfg.visualization.history_size)
# Init the visualization visdom env.
if cfg.visualization.visdom:
viz = Visdom(
server=cfg.visualization.visdom_server,
port=cfg.visualization.visdom_port,
use_incoming_socket=False,
)
else:
viz = None
# Load the training/validation data.
train_dataset, val_dataset, _ = get_nerf_datasets(
dataset_name=cfg.data.dataset_name,
image_size=cfg.data.image_size,
)
if cfg.data.precache_rays:
# Precache the projection rays.
model.eval()
with torch.no_grad():
for dataset in (train_dataset, val_dataset):
cache_cameras = [e["camera"].to(device) for e in dataset]
cache_camera_hashes = [e["camera_idx"] for e in dataset]
model.precache_rays(cache_cameras, cache_camera_hashes)
train_dataloader = torch.utils.data.DataLoader(
train_dataset,
batch_size=1,
shuffle=True,
num_workers=0,
collate_fn=trivial_collate,
)
# The validation dataloader is just an endless stream of random samples.
val_dataloader = torch.utils.data.DataLoader(
val_dataset,
batch_size=1,
num_workers=0,
collate_fn=trivial_collate,
sampler=torch.utils.data.RandomSampler(
val_dataset,
replacement=True,
num_samples=cfg.optimizer.max_epochs,
),
)
# Set the model to the training mode.
model.train()
# Run the main training loop.
for epoch in range(start_epoch, cfg.optimizer.max_epochs):
stats.new_epoch() # Init a new epoch.
for iteration, batch in enumerate(train_dataloader):
image, camera, camera_idx = batch[0].values()
image = image.to(device)
camera = camera.to(device)
optimizer.zero_grad()
# Run the forward pass of the model.
nerf_out, metrics = model(
camera_idx if cfg.data.precache_rays else None,
camera,
image,
)
# The loss is a sum of coarse and fine MSEs
loss = metrics["mse_coarse"] + metrics["mse_fine"]
# Take the training step.
loss.backward()
optimizer.step()
# Update stats with the current metrics.
stats.update(
{"loss": float(loss), **metrics},
stat_set="train",
)
if iteration % cfg.stats_print_interval == 0:
stats.print(stat_set="train")
# Update the visualization cache.
if viz is not None:
visuals_cache.append(
{
"camera": camera.cpu(),
"camera_idx": camera_idx,
"image": image.cpu().detach(),
"rgb_fine": nerf_out["rgb_fine"].cpu().detach(),
"rgb_coarse": nerf_out["rgb_coarse"].cpu().detach(),
"rgb_gt": nerf_out["rgb_gt"].cpu().detach(),
"coarse_ray_bundle": nerf_out["coarse_ray_bundle"],
}
)
# Adjust the learning rate.
lr_scheduler.step()
# Validation
if epoch % cfg.validation_epoch_interval == 0 and epoch > 0:
# Sample a validation camera/image.
val_batch = next(val_dataloader.__iter__())
val_image, val_camera, camera_idx = val_batch[0].values()
val_image = val_image.to(device)
val_camera = val_camera.to(device)
# Activate eval mode of the model (lets us do a full rendering pass).
model.eval()
with torch.no_grad():
val_nerf_out, val_metrics = model(
camera_idx if cfg.data.precache_rays else None,
val_camera,
val_image,
)
# Update stats with the validation metrics.
stats.update(val_metrics, stat_set="val")
stats.print(stat_set="val")
if viz is not None:
# Plot that loss curves into visdom.
stats.plot_stats(
viz=viz,
visdom_env=cfg.visualization.visdom_env,
plot_file=None,
)
# Visualize the intermediate results.
visualize_nerf_outputs(
val_nerf_out, visuals_cache, viz, cfg.visualization.visdom_env
)
# Set the model back to train mode.
model.train()
# Checkpoint.
if (
epoch % cfg.checkpoint_epoch_interval == 0
and len(cfg.checkpoint_path) > 0
and epoch > 0
):
print(f"Storing checkpoint {checkpoint_path}.")
data_to_store = {
"model": model.state_dict(),
"optimizer": optimizer.state_dict(),
"stats": pickle.dumps(stats),
}
torch.save(data_to_store, checkpoint_path)
if __name__ == "__main__":
main()