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nerfstudio/mattport/structures/rays.py
T

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2.6 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
class RaySamples:
"""_summary_"""
def __init__(
self,
ts: TensorType["num_rays", "num_samples"],
ray_bundle: RayBundle,
) -> None:
self.ray_bundle = ray_bundle
self.ts = ts
self.positions = self.get_positions(ray_bundle)
self.directions = ray_bundle.directions.unsqueeze(1).repeat(1, self.positions.shape[1], 1)
self.deltas = self.get_deltas()
def get_positions(self, ray_bundle: RayBundle) -> TensorType["num_rays", "num_samples", 3]:
"""Returns positions."""
return ray_bundle.origins[:, None] + self.ts[:, :, None] * ray_bundle.directions[:, None]
def get_deltas(self) -> TensorType[..., "num_samples"]:
"""Returns deltas."""
dists = self.ts[..., 1:] - self.ts[..., :-1]
dists = torch.cat([dists, dists[..., -1:]], -1) # [N_rays, N_samples]
deltas = dists * torch.norm(self.ray_bundle.directions[..., None, :], dim=-1)
return deltas