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nerfstudio/nerfactory/fields/base.py
2022-07-31 18:22:57 -07:00

109 lines
4.1 KiB
Python

# Copyright 2022 The Plenoptix Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Base class for the graphs.
"""
from abc import abstractmethod
from typing import Dict, Optional, Tuple
import torch
from torch import nn
from torchtyping import TensorType
from nerfactory.cameras.rays import Frustums, RaySamples
from nerfactory.fields.modules.field_heads import FieldHeadNames
class Field(nn.Module):
"""Base class for fields."""
def density_fn(self, positions):
"""Returns only the density. Used primarily with the density grid."""
# Need to figure out a better way to descibe positions with a ray.
ray_samples = RaySamples(
frustums=Frustums(
origins=positions,
directions=torch.ones_like(positions),
starts=torch.zeros_like(positions[..., :1]),
ends=torch.zeros_like(positions[..., :1]),
pixel_area=torch.ones_like(positions[..., :1]),
)
)
density, _ = self.get_density(ray_samples)
return density
@abstractmethod
def get_density(self, ray_samples: RaySamples) -> Tuple[TensorType[..., 1], TensorType[..., "num_features"]]:
"""Computes and returns the densities.
Args:
ray_samples (RaySamples): Samples locations to compute density.
Returns:
Tuple[TensorType[...,1], TensorType[...,"num_features"]]: A tensor of densities and a tensor of features.
"""
@abstractmethod
def get_outputs(
self, ray_samples: RaySamples, density_embedding: Optional[TensorType] = None
) -> Dict[FieldHeadNames, TensorType]:
"""Computes and returns the colors.
Args:
ray_samples (RaySamples): Samples locations to compute outputs.
density_embedding (TensorType, optional): Density embeddings to condition on.
Returns:
Dict[FieldHeadNames, TensorType]: Output field values.
"""
def forward(self, ray_samples: RaySamples):
"""Evaluates the field at points along the ray.
Args:
ray_samples (RaySamples): Samples to evaluate field on.
"""
valid_mask = ray_samples.valid_mask
if valid_mask is not None:
# Hacky handling of empty masks. Tests on a single ray but doesn't use results
if not valid_mask.any():
ray_samples = RaySamples(frustums=Frustums.get_mock_frustum().to(valid_mask.device))
else:
ray_samples = ray_samples.apply_masks()
density_masked, density_embedding_masked = self.get_density(ray_samples)
field_outputs_masked = self.get_outputs(ray_samples, density_embedding=density_embedding_masked)
field_outputs = {}
for k, value in field_outputs_masked.items():
zeros = torch.zeros(
*valid_mask.shape[:-1], value.shape[-1], dtype=value.dtype, device=valid_mask.device
)
if valid_mask.any():
zeros[valid_mask[..., 0]] = value
else:
zeros[0, :] = value
field_outputs[k] = zeros
density = torch.zeros(valid_mask.shape, dtype=density_masked.dtype, device=valid_mask.device)
if valid_mask.any():
density[valid_mask[..., 0]] = density_masked
else:
density, density_embedding = self.get_density(ray_samples)
field_outputs = self.get_outputs(ray_samples, density_embedding=density_embedding)
field_outputs[FieldHeadNames.DENSITY] = density # type: ignore
return field_outputs