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nerfstudio/mattport/structures/rays.py
T

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2.9 KiB
Python

"""
Some ray datastructures.
"""
import random
from dataclasses import dataclass
from typing import Optional
import torch
from torchtyping import TensorType
@dataclass
class RayBundle:
"""_summary_
Returns:
_type_: _description_
"""
origins: TensorType["num_rays", 3]
directions: TensorType["num_rays", 3]
camera_indices: Optional[TensorType["num_rays"]] = None
def to_camera_ray_bundle(self, image_height, image_width) -> "CameraRayBundle":
"""_summary_
Args:
image_height (_type_): _description_
image_width (_type_): _description_
Returns:
CameraRayBundle: _description_
"""
camera_ray_bundle = CameraRayBundle(
origins=self.origins.view(image_height, image_width, 3),
directions=self.directions.view(image_height, image_width, 3),
)
return camera_ray_bundle
def __len__(self):
num_rays = self.origins.shape[0]
return num_rays
def sample(self, num_rays: int):
"""Returns a RayBundle as a subset of rays.
Args:
num_rays (int):
Returns:
RayBundle: _description_
"""
assert num_rays <= len(self)
indices = random.sample(range(len(self)), k=num_rays)
return RayBundle(
origins=self.origins[indices],
directions=self.directions[indices],
camera_indices=self.camera_indices[indices],
)
@dataclass
class CameraRayBundle:
"""_summary_"""
origins: TensorType["image_height", "image_width", 3]
directions: TensorType["image_height", "image_width", 3]
camera_index: int = None
@dataclass
class RaySamples:
"""_summary_
Args:
t_min: maximum times
t_max: minimum times
ts: time steps
"""
t_min: TensorType["num_rays"]
t_max: TensorType["num_rays"]
ts: TensorType["num_rays", "num_samples+1"] # TODO(ethan): check with Matt about this. 2nd dimension is num_samples+1
def get_positions(self, ray_bundle: RayBundle) -> TensorType["num_rays", "num_samples", 3]:
"""Returns positions."""
# TODO(ethan): check with Matt about this
t_mid = (self.ts[:, 1:] + self.ts[:, :-1]) / 2 # (num_rays, num_samples)
return ray_bundle.origins[:, None] + t_mid[:, :, None] * ray_bundle.directions[:, None]
def get_starts(self):
"""_summary_
Returns:
_type_: _description_
"""
t_mid = (self.ts[:, 1:] + self.ts[:, :-1]) / 2
return torch.cat([self.t_min[:, None], t_mid], dim=-1)
def get_ends(self):
"""_summary_
Returns:
_type_: _description_
"""
t_mid = (self.ts[:, 1:] + self.ts[:, :-1]) / 2
return torch.cat([t_mid, self.t_max[:, None]], dim=-1)
def get_deltas(self) -> TensorType["num_samples"]:
"""Returns deltas."""
return self.get_ends() - self.get_starts()