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# SPDX-FileCopyrightText: Copyright (c) 2021-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved. | |
# SPDX-License-Identifier: LicenseRef-NvidiaProprietary | |
# | |
# NVIDIA CORPORATION, its affiliates and licensors retain all intellectual | |
# property and proprietary rights in and to this material, related | |
# documentation and any modifications thereto. Any use, reproduction, | |
# disclosure or distribution of this material and related documentation | |
# without an express license agreement from NVIDIA CORPORATION or | |
# its affiliates is strictly prohibited. | |
# | |
# Modified by Jiale Xu | |
# The modifications are subject to the same license as the original. | |
""" | |
The ray sampler is a module that takes in camera matrices and resolution and batches of rays. | |
Expects cam2world matrices that use the OpenCV camera coordinate system conventions. | |
""" | |
import torch | |
class RaySampler(torch.nn.Module): | |
def __init__(self): | |
super().__init__() | |
self.ray_origins_h, self.ray_directions, self.depths, self.image_coords, self.rendering_options = None, None, None, None, None | |
def forward(self, cam2world_matrix, intrinsics, render_size): | |
""" | |
Create batches of rays and return origins and directions. | |
cam2world_matrix: (N, 4, 4) | |
intrinsics: (N, 3, 3) | |
render_size: int | |
ray_origins: (N, M, 3) | |
ray_dirs: (N, M, 2) | |
""" | |
dtype = cam2world_matrix.dtype | |
device = cam2world_matrix.device | |
N, M = cam2world_matrix.shape[0], render_size**2 | |
cam_locs_world = cam2world_matrix[:, :3, 3] | |
fx = intrinsics[:, 0, 0] | |
fy = intrinsics[:, 1, 1] | |
cx = intrinsics[:, 0, 2] | |
cy = intrinsics[:, 1, 2] | |
sk = intrinsics[:, 0, 1] | |
uv = torch.stack(torch.meshgrid( | |
torch.arange(render_size, dtype=dtype, device=device), | |
torch.arange(render_size, dtype=dtype, device=device), | |
indexing='ij', | |
)) | |
uv = uv.flip(0).reshape(2, -1).transpose(1, 0) | |
uv = uv.unsqueeze(0).repeat(cam2world_matrix.shape[0], 1, 1) | |
x_cam = uv[:, :, 0].view(N, -1) * (1./render_size) + (0.5/render_size) | |
y_cam = uv[:, :, 1].view(N, -1) * (1./render_size) + (0.5/render_size) | |
z_cam = torch.ones((N, M), dtype=dtype, device=device) | |
x_lift = (x_cam - cx.unsqueeze(-1) + cy.unsqueeze(-1)*sk.unsqueeze(-1)/fy.unsqueeze(-1) - sk.unsqueeze(-1)*y_cam/fy.unsqueeze(-1)) / fx.unsqueeze(-1) * z_cam | |
y_lift = (y_cam - cy.unsqueeze(-1)) / fy.unsqueeze(-1) * z_cam | |
cam_rel_points = torch.stack((x_lift, y_lift, z_cam, torch.ones_like(z_cam)), dim=-1).to(dtype) | |
_opencv2blender = torch.tensor([ | |
[1, 0, 0, 0], | |
[0, -1, 0, 0], | |
[0, 0, -1, 0], | |
[0, 0, 0, 1], | |
], dtype=dtype, device=device).unsqueeze(0).repeat(N, 1, 1) | |
cam2world_matrix = torch.bmm(cam2world_matrix, _opencv2blender) | |
world_rel_points = torch.bmm(cam2world_matrix, cam_rel_points.permute(0, 2, 1)).permute(0, 2, 1)[:, :, :3] | |
ray_dirs = world_rel_points - cam_locs_world[:, None, :] | |
ray_dirs = torch.nn.functional.normalize(ray_dirs, dim=2).to(dtype) | |
ray_origins = cam_locs_world.unsqueeze(1).repeat(1, ray_dirs.shape[1], 1) | |
return ray_origins, ray_dirs | |
class OrthoRaySampler(torch.nn.Module): | |
def __init__(self): | |
super().__init__() | |
self.ray_origins_h, self.ray_directions, self.depths, self.image_coords, self.rendering_options = None, None, None, None, None | |
def forward(self, cam2world_matrix, ortho_scale, render_size): | |
""" | |
Create batches of rays and return origins and directions. | |
cam2world_matrix: (N, 4, 4) | |
ortho_scale: float | |
render_size: int | |
ray_origins: (N, M, 3) | |
ray_dirs: (N, M, 3) | |
""" | |
N, M = cam2world_matrix.shape[0], render_size**2 | |
uv = torch.stack(torch.meshgrid( | |
torch.arange(render_size, dtype=torch.float32, device=cam2world_matrix.device), | |
torch.arange(render_size, dtype=torch.float32, device=cam2world_matrix.device), | |
indexing='ij', | |
)) | |
uv = uv.flip(0).reshape(2, -1).transpose(1, 0) | |
uv = uv.unsqueeze(0).repeat(cam2world_matrix.shape[0], 1, 1) | |
x_cam = uv[:, :, 0].view(N, -1) * (1./render_size) + (0.5/render_size) | |
y_cam = uv[:, :, 1].view(N, -1) * (1./render_size) + (0.5/render_size) | |
z_cam = torch.zeros((N, M), device=cam2world_matrix.device) | |
x_lift = (x_cam - 0.5) * ortho_scale | |
y_lift = (y_cam - 0.5) * ortho_scale | |
cam_rel_points = torch.stack((x_lift, y_lift, z_cam, torch.ones_like(z_cam)), dim=-1) | |
_opencv2blender = torch.tensor([ | |
[1, 0, 0, 0], | |
[0, -1, 0, 0], | |
[0, 0, -1, 0], | |
[0, 0, 0, 1], | |
], dtype=torch.float32, device=cam2world_matrix.device).unsqueeze(0).repeat(N, 1, 1) | |
cam2world_matrix = torch.bmm(cam2world_matrix, _opencv2blender) | |
ray_origins = torch.bmm(cam2world_matrix, cam_rel_points.permute(0, 2, 1)).permute(0, 2, 1)[:, :, :3] | |
ray_dirs_cam = torch.stack([ | |
torch.zeros((N, M), device=cam2world_matrix.device), | |
torch.zeros((N, M), device=cam2world_matrix.device), | |
torch.ones((N, M), device=cam2world_matrix.device), | |
], dim=-1) | |
ray_dirs = torch.bmm(cam2world_matrix[:, :3, :3], ray_dirs_cam.permute(0, 2, 1)).permute(0, 2, 1) | |
return ray_origins, ray_dirs | |