File size: 9,815 Bytes
874cec4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3ed17f3
874cec4
 
 
 
 
 
 
 
 
 
 
 
3ed17f3
 
 
874cec4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3ed17f3
 
 
874cec4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3ed17f3
874cec4
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
import numpy as np
import torch,math
from PIL import Image
import torchvision
from easydict import EasyDict as edict

import torch.nn.functional as F
import torch.nn as nn
import random
from einops import repeat, rearrange

from source.rendering.point_sampler import perturb_points_per_ray
from source.rendering.aabb import intersect_aabb_end
from source.rendering.transform_perspective import compose_rotmat


def get_normal_coord(W, H, device='cpu'):
    '''
    Standard equirectangular panorama coordinate normalization.
    W: panorama width
    H: panorama height
    device: target device, usually `cpu` or `cuda`
    Returns:
        normalized_coords: tensor with shape (W, H, 3)
    '''
    # Create linear coordinates from 0 to W-1 and 0 to H-1.
    y = torch.linspace(0, W - 1, W, device=device)
    x = torch.linspace(0, H - 1, H, device=device)
    
    # Build the mesh grid.
    Y, X = torch.meshgrid(y, x, indexing='ij')  # Y: (W, H), X: (W, H)
    
    # Convert the grid to longitude and latitude.
    phi = -(Y / (W - 1) - 0.5) * 2 * math.pi + (math.pi / 2)         # longitude in [-pi, pi]
    theta = -(0.5 - X / (H - 1)) * math.pi           # latitude in [-pi/2, pi/2]
    
    # Compute normalized 3D coordinates.
    cos_theta = torch.cos(theta)
    sin_theta = torch.sin(theta)
    cos_phi = torch.cos(phi)
    sin_phi = torch.sin(phi)
    
    normalized_coords = torch.stack([
        cos_theta * cos_phi,   # x axis
        sin_theta,             # y axis
        cos_theta * sin_phi    # z axis
    ], dim=2)  # Shape: (W, H, 3)
    # reshape to (H, W, 3)
    normalized_coords = normalized_coords.permute(1, 0, 2)
    
    return normalized_coords



def get_original_coord(W,H,full=True,c2w=None):
    '''
    W: width of pano
    H: height of pano
    if dataset is CVACT, ful=True, return the original coordinate of CVACT
    if dataset is CVUSA, ful=False,
    fill = False only used for CVUSA dataset
    '''
    normalized_coords = get_normal_coord(W,H)


    if c2w is None:
        RollPitchYaw = [0,0,0]
        R_c2w = compose_rotmat(RollPitchYaw[0], RollPitchYaw[1], RollPitchYaw[2])
        # to torch and then to the devidece of normalized_coords
        # if numpy, to torch
        if isinstance(R_c2w, np.ndarray):
            R_c2w = torch.from_numpy(R_c2w).to(normalized_coords.device).float()
    ray_directions = torch.einsum('ij,hwj->hwi', R_c2w, normalized_coords)
    # ray_directions = np.einsum('ij,hwj->hwi', R_c2w, normalized_coords)  # [H, W, 3]

    # Normalize ray directions by torch ops
    ray_directions = ray_directions / torch.norm(ray_directions, dim=-1, keepdim=True)
    # ray_directions = ray_directions / np.linalg.norm(ray_directions, axis=-1, keepdims=True)
    return ray_directions  

class Point_sampler_pano(torch.nn.Module):
    # designed for street view panorama image
    def __init__(self,
                pano_direction,
                sample_total_length=None,
                num_points=300,
                perturbation_strategy = 'uniform',
                aabb_strict =False,
                data_type = None,
                ):
        super().__init__()
        self.sample_total_length = np.sqrt(1.5**2+1.5**2+1.9**2)
        

        self.pano_direction = pano_direction
        self.num_points = num_points
        if not aabb_strict:
            self.sample_len = ((torch.arange(self.num_points)+1)*(self.sample_total_length/self.num_points)).float()

        self.voxel_low = -1
        self.voxel_max = 1

        self.perturbation_strategy = perturbation_strategy
        self.aabb_strict = aabb_strict

    @torch.no_grad()
    def forward(self,
                batch_size,
                position=None,
                ):
        device = position.device
        origin_opensfm = position[:,None,None,:].to(device) # w -h z
        pano_direction = self.pano_direction[...,None].to(device) # b h w c # in opensfm coordinate
        output = edict()

        H,W = pano_direction.shape[1],pano_direction.shape[2]


        rays_world = repeat(pano_direction, '1 h w c 1 -> b h w c', b=batch_size )
        ray_origins = repeat(origin_opensfm, 'b 1 1 c -> b h w c', h=H, w=W )

        if self.aabb_strict:
            sample_total_length = intersect_aabb_end(ray_origins,rays_world,min=0,max=self.sample_total_length)
            sample_total_length = rearrange(sample_total_length, '(b h w) -> b h w 1', b=batch_size, h = H, w = W )
            output.radii_raw = (torch.arange(self.num_points)+1)[None,None,None,:].to(sample_total_length.device) * (sample_total_length/self.num_points)
        else:
            depth = self.sample_len[None,None,None,None,:]
            output.radii_raw  = repeat(depth, '1 1 1 1 k -> b h w k', b=batch_size, h = H, w = W )  # (1,h,w,1,k) -> (batch_size, h, w, k)
        output.radii =  perturb_points_per_ray(output.radii_raw,strategy=self.perturbation_strategy)
        sample_point = ray_origins.unsqueeze(-1) + rays_world.unsqueeze(-1) * output.radii.unsqueeze(-2)

        

        output.points_world =  rearrange(sample_point, 'b h w c k -> b h w k c').clone()
        output.ray_origins = ray_origins.clone()
        output.ray_origins[...,1] = -output.ray_origins[...,1]
        output.rays_world = rays_world.clone()
        output.rays_world[...,1] = -output.rays_world[...,1]
        output.points_world[...,1] = -output.points_world[...,1]
        return  output

                
        


def get_sat_ori(resolution,position_scale_factor=1):
    y_range =  (torch.arange(resolution,dtype=torch.float32,)+0.5)/(0.5*resolution)-1
    x_range = (torch.arange(resolution,dtype=torch.float32,)+0.5)/(0.5*resolution)-1
    Y,X = torch.meshgrid(y_range,x_range)
    Y = Y*position_scale_factor
    X = X*position_scale_factor
    Z = torch.ones_like(Y) # z=1 means the highest position in coordinate, in dimension 1
    xy_grid = torch.stack([X,Z,Y],dim=-1)[None,:,:]
    return xy_grid


class Point_sampler_ortho(torch.nn.Module):
    '''
    point sampler designed for ortho image,


    '''
    def __init__(self,
                 num_points,
                 resolution=256,
                 perturbation_strategy = 'uniform',
                 position_scale_factor = 1,
                 render_size = 128,
                 ):
        super().__init__()
        self.perturbation_strategy = perturbation_strategy
        # not used any more
        self.resolution = resolution
        self.sat_ori = get_sat_ori(self.resolution,position_scale_factor)[...,None]
        self.sat_dir  = torch.tensor([0,-1,0])[None,None,None,:,None]
        self.sample_total_length = 2
        self.num_points = num_points
        self.sample_len = ((torch.arange(self.num_points)+1)*(self.sample_total_length/self.num_points))
        self.render_size = render_size

    @torch.no_grad()
    def forward(self,
                batch_size,
                random_crop=True,
                crop_type=None,
                ):
        device = self.sat_ori.device if self.sat_ori.is_cuda else (torch.device("cuda") if torch.cuda.is_available() else torch.device("cpu"))
        depth = self.sample_len[None,None,None,None,:].to(device).float()
        sat_dir = self.sat_dir.to(device)
        # sample_point = self.sat_ori + self.sat_dir * depth
        output = edict()
        if random_crop:
            if crop_type == 'crop':
                assert self.render_size < self.resolution
                start_h = random.randint(0,self.resolution-self.render_size-1)
                start_w = random.randint(0,self.resolution-self.render_size-1)
                output.idx = [start_h,start_w]
                sat_ori = self.sat_ori[:,start_h:start_h+self.render_size,start_w:start_w+self.render_size,:]
            elif crop_type == 'resize':
                sat_ori = rearrange(self.sat_ori,'b h w c 1 -> b c h w')
                sat_ori = F.interpolate(sat_ori,scale_factor=0.5,mode='bilinear')
                sat_ori = rearrange(sat_ori,'b c h w -> b h w c 1')
            else:
                raise NotImplementedError
        else:
            sat_ori = self.sat_ori
            self.render_size = self.resolution
            assert self.render_size == self.resolution
        sat_ori = sat_ori.to(device)
        
        # sat_ori = self.position_scale_factor * sat_ori
        # output.points_world =  repeat(grid, '1 k h w c -> b h w k c', b=batch_size)
        output.rays_world = repeat(sat_dir, '1 1 1 c 1 -> b h w c', b=batch_size,  h = self.render_size, w = self.render_size )[...,[0,2,1]]  # (1,h,w,3,1) -> (batch_size, h, w, 3)
        output.radii_raw  = repeat(depth, '1 1 1 1 k -> b h w k', b=batch_size, h = self.render_size, w = self.render_size )  # (1,h,w,1,k) -> (batch_size, h, w, k, 1)
        output.ray_origins = repeat(sat_ori, '1 h w c 1 -> b h w c',b=batch_size)[...,[0,2,1]]
        output.radii =  perturb_points_per_ray(output.radii_raw,strategy=self.perturbation_strategy)

        sample_point = sat_ori + sat_dir * output.radii.unsqueeze(-2)
        
        grid = sample_point.permute(0,4,1,2,3)[...,[0,2,1]] # has a change back, from height in the second dimension to height in the last dimension
        # grid[...,2]   = ((grid[...,2]-self.voxel_low)/(self.voxel_max-self.voxel_low))*2-1
        # grid = grid.float()
        output.points_world =  rearrange(grid, 'b k h w c -> b h w k c')
        return  output





# class RGB_Reprerenter(torch.nn.Module):
#     def __init__(self,
#                 ):
#         super().__init__()

#     def forward(self,
#                 points,
#                 image,
#                 ):
#         point_h_w = points[...,0:2].unsqueeze(2) # b, N, 1, 2
#         rgb_feature = F.grid_sample(image,point_h_w).squeeze(-1).permute(0,2,1) # b, C, N, 1 -> b, N, C
#         return rgb_feature