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nerfstudio/nerfactory/fields/density_field.py
Ethan Weber 383a6075cc
[wip] proposal network sampler (#534)
* initial running code

* dozer and poster 6K experiments

* code reorganization

* removed print

* black
2022-09-25 16:56:29 -07:00

113 lines
3.9 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.
"""
Proposal network field.
"""
from typing import Optional
import numpy as np
from torch.nn.parameter import Parameter
from torchtyping import TensorType
from nerfactory.cameras.rays import RaySamples
from nerfactory.datamanagers.structs import SceneBounds
from nerfactory.fields.base import Field
from nerfactory.fields.modules.spatial_distortions import SpatialDistortion
from nerfactory.utils.activations import trunc_exp
try:
import tinycudann as tcnn
except ImportError:
# tinycudann module doesn't exist
pass
class DensityField(Field):
"""A lightweight density field module.
Args:
aabb: parameters of scene aabb bounds
num_layers: number of hidden layers
hidden_dim: dimension of hidden layers
spatial_distortion: spatial distortion module
"""
def __init__(
self, aabb, num_layers: int = 2, hidden_dim: int = 64, spatial_distortion: Optional[SpatialDistortion] = None
) -> None:
super().__init__()
self.aabb = Parameter(aabb, requires_grad=False)
self.spatial_distortion = spatial_distortion
num_levels = 16
# max_res = 2048
max_res = 4096
base_res = 16
growth_factor = np.exp((np.log(max_res) - np.log(base_res)) / (num_levels - 1))
self.direction_encoding = tcnn.Encoding(
n_input_dims=3,
encoding_config={
"otype": "SphericalHarmonics",
"degree": 4,
},
)
self.mlp_base = tcnn.NetworkWithInputEncoding(
n_input_dims=3,
n_output_dims=1,
encoding_config={
"otype": "HashGrid",
"n_levels": num_levels,
"n_features_per_level": 2,
"log2_hashmap_size": 19,
"base_resolution": base_res,
"per_level_scale": growth_factor,
},
network_config={
"otype": "FullyFusedMLP",
"activation": "ReLU",
"output_activation": "None",
"n_neurons": hidden_dim,
"n_hidden_layers": num_layers - 1,
},
)
def get_density(self, ray_samples: RaySamples):
if self.spatial_distortion is not None:
positions = self.spatial_distortion(ray_samples.frustums.get_positions())
positions = (positions + 2.0) / 4.0
else:
positions = SceneBounds.get_normalized_positions(ray_samples.frustums.get_positions(), self.aabb)
positions_flat = positions.view(-1, 3)
# assert all positions are in the range [0, 1]
# otherwise print min and max values
# assert torch.all(positions >= 0.0) and torch.all(
# positions <= 1.0
# ), f"positions: {positions.min()} {positions.max()}"
density_before_activation = self.mlp_base(positions_flat).view(*ray_samples.frustums.shape, -1)
# Rectifying the density with an exponential is much more stable than a ReLU or
# softplus, because it enables high post-activation (float32) density outputs
# from smaller internal (float16) parameters.
density = trunc_exp(density_before_activation.to(positions))
return density, None
def get_outputs(self, ray_samples: RaySamples, density_embedding: Optional[TensorType] = None):
return {}