File size: 8,298 Bytes
8d5039c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch
import numpy as np
import torch.nn as nn
import torch.nn.functional as F
from model import pointnet_util
from model.model_utils import *


# idx = pointnet_util.ball_query(self.radius, self.nsample, xyz, new_xyz)
# # _, idx = pointnet_util.knn_query(self.nsample, xyz, new_xyz)
# xyz_trans = xyz.permute(0, 2, 1)
# grouped_xyz = pointnet_util.grouping_operation(xyz_trans, idx)  # (B, 3, npoint, nsample)
# grouped_xyz -= new_xyz.permute(0, 2, 1).unsqueeze(-1)


def get_model():
    return PointNet2()


class PointNet2(nn.Module):
    def __init__(self, in_channel=3):
        super().__init__()
        self.sa1 = PointNetSAModule(256, 0.1, 16, in_channel, [32, 32, 64])
        self.sa2 = PointNetSAModule(128, 0.1, 16, 64, [64, 64, 128])
        self.sa3 = PointNetSAModule(64, 0.2, 16, 128, [128, 128, 256])
        self.sa4 = PointNetSAModule(16, 0.4, 16, 256, [256, 256, 512])
        self.fp4 = PointNetFPModule(768, [256, 256])
        self.fp3 = PointNetFPModule(384, [256, 256])
        self.fp2 = PointNetFPModule(320, [256, 128])
        self.fp1 = PointNetFPModule(128, [128, 128, 128])
        self.shared_fc = Conv1dBN(128, 128)
        self.drop = nn.Dropout(0.5)
        self.offset_fc = nn.Conv1d(128, 3, 1)
        self.cls_fc = nn.Conv1d(128, 1, 1)

    def forward(self, batch_dict):
        xyz = batch_dict['points']
        fea = xyz
        l0_fea = fea.permute(0, 2, 1)
        l0_xyz = xyz

        l1_xyz, l1_fea = self.sa1(l0_xyz, l0_fea)
        l2_xyz, l2_fea = self.sa2(l1_xyz, l1_fea)
        l3_xyz, l3_fea = self.sa3(l2_xyz, l2_fea)
        l4_xyz, l4_fea = self.sa4(l3_xyz, l3_fea)

        l3_fea = self.fp4(l3_xyz, l4_xyz, l3_fea, l4_fea)
        l2_fea = self.fp3(l2_xyz, l3_xyz, l2_fea, l3_fea)
        l1_fea = self.fp2(l1_xyz, l2_xyz, l1_fea, l2_fea)
        l0_fea = self.fp1(l0_xyz, l1_xyz, None, l1_fea)

        x = self.drop(self.shared_fc(l0_fea))
        pred_offset = self.offset_fc(x).permute(0, 2, 1)
        pred_cls = self.cls_fc(x).permute(0, 2, 1)
        batch_dict['point_features'] = l0_fea.permute(0, 2, 1)
        batch_dict['point_pred_score'] = torch.sigmoid(pred_cls).squeeze(-1)
        batch_dict['point_pred_offset'] = pred_offset
        return batch_dict


class PointNetSAModuleMSG(nn.Module):
    def __init__(self, npoint, radii, nsamples, in_channel, mlps, use_xyz=True):
        """
        PointNet Set Abstraction Module
        :param npoint: int
        :param radii: list of float, radius in ball_query
        :param nsamples: list of int, number of samples in ball_query
        :param in_channel: int
        :param mlps: list of list of int
        :param use_xyz: bool
        """
        super().__init__()
        assert len(radii) == len(nsamples) == len(mlps)
        mlps = [[in_channel] + mlp for mlp in mlps]
        self.npoint = npoint
        self.groupers = nn.ModuleList()
        self.mlps = nn.ModuleList()

        for i in range(len(radii)):
            r = radii[i]
            nsample = nsamples[i]
            mlp = mlps[i]
            if use_xyz:
                mlp[0] += 3
            self.groupers.append(QueryAndGroup(r, nsample, use_xyz) if npoint is not None else GroupAll(use_xyz))
            self.mlps.append(Conv2ds(mlp))

    def forward(self, xyz, features, new_xyz=None):
        """
        :param xyz: (B, N, 3) tensor of the xyz coordinates of the features
        :param features: (B, C, N) tensor of the descriptors of the the features
        :param new_xyz:
        :return:
            new_xyz: (B, npoint, 3) tensor of the new features' xyz
            new_features: (B, C1, npoint) tensor of the new_features descriptors
        """
        new_features_list = []
        xyz = xyz.contiguous()
        xyz_flipped = xyz.permute(0, 2, 1)
        if new_xyz is None:
            new_xyz = pointnet_util.gather_operation(xyz_flipped, pointnet_util.furthest_point_sample(
                xyz, self.npoint, 1.0, 0.0)).permute(0, 2, 1) if self.npoint is not None else None

        for i in range(len(self.groupers)):
            new_features = self.groupers[i](xyz, new_xyz, features)  # (B, C, npoint, nsample)

            new_features = self.mlps[i](new_features)  # (B, mlp[-1], npoint, nsample)
            new_features = F.max_pool2d(new_features, kernel_size=[1, new_features.size(3)]).squeeze(-1)
            new_features_list.append(new_features)

        return new_xyz, torch.cat(new_features_list, dim=1)


class PointNetSAModule(PointNetSAModuleMSG):
    def __init__(self, npoint, radius, nsample, in_channel, mlp, use_xyz=True):
        super().__init__(npoint, [radius], [nsample], in_channel, [mlp], use_xyz)


class PointNetFPModule(nn.Module):
    def __init__(self, in_channel, mlp):
        super().__init__()
        self.mlp = Conv2ds([in_channel] + mlp)

    def forward(self, pts1, pts2, fea1, fea2):
        """
        :param pts1: (B, n, 3) 
        :param pts2: (B, m, 3)  n > m
        :param fea1: (B, C1, n)
        :param fea2: (B, C2, m)
        :return:
            new_features: (B, mlp[-1], n)
        """
        if pts2 is not None:
            dist, idx = pointnet_util.three_nn(pts1, pts2)
            dist_recip = 1.0 / (dist + 1e-8)
            norm = torch.sum(dist_recip, dim=2, keepdim=True)
            weight = dist_recip / norm

            interpolated_feats = pointnet_util.three_interpolate(fea2, idx, weight)
        else:
            interpolated_feats = fea2.expand(*fea2.size()[0:2], pts1.size(1))

        if fea1 is not None:
            new_features = torch.cat([interpolated_feats, fea1], dim=1)  # (B, C2 + C1, n)
        else:
            new_features = interpolated_feats

        new_features = new_features.unsqueeze(-1)
        new_features = self.mlp(new_features)

        return new_features.squeeze(-1)


class QueryAndGroup(nn.Module):
    def __init__(self, radius: float, nsample: int, use_xyz: bool = True):
        """
        :param radius: float, radius of ball
        :param nsample: int, maximum number of features to gather in the ball
        :param use_xyz:
        """
        super().__init__()
        self.radius, self.nsample, self.use_xyz = radius, nsample, use_xyz

    def forward(self, xyz: torch.Tensor, new_xyz: torch.Tensor, features: torch.Tensor = None):
        """
        :param xyz: (B, N, 3) xyz coordinates of the features
        :param new_xyz: (B, npoint, 3) centroids
        :param features: (B, C, N) descriptors of the features
        :return:
            new_features: (B, 3 + C, npoint, nsample)
        """
        idx = pointnet_util.ball_query(self.radius, self.nsample, xyz, new_xyz)
        # _, idx = pointnet_util.knn_query(self.nsample, xyz, new_xyz)
        xyz_trans = xyz.permute(0, 2, 1)
        grouped_xyz = pointnet_util.grouping_operation(xyz_trans, idx)  # (B, 3, npoint, nsample)
        grouped_xyz -= new_xyz.permute(0, 2, 1).unsqueeze(-1)

        if features is not None:
            grouped_features = pointnet_util.grouping_operation(features, idx)
            if self.use_xyz:
                new_features = torch.cat([grouped_xyz, grouped_features], dim=1)  # (B, C + 3, npoint, nsample)
            else:
                new_features = grouped_features
        else:
            assert self.use_xyz, "Cannot have not features and not use xyz as a feature!"
            new_features = grouped_xyz

        return new_features


class GroupAll(nn.Module):
    def __init__(self, use_xyz: bool = True):
        super().__init__()
        self.use_xyz = use_xyz

    def forward(self, xyz: torch.Tensor, new_xyz: torch.Tensor, features: torch.Tensor = None):
        """
        :param xyz: (B, N, 3) xyz coordinates of the features
        :param new_xyz: ignored
        :param features: (B, C, N) descriptors of the features
        :return:
            new_features: (B, C + 3, 1, N)
        """
        grouped_xyz = xyz.permute(0, 2, 1).unsqueeze(2)
        if features is not None:
            grouped_features = features.unsqueeze(2)
            if self.use_xyz:
                new_features = torch.cat([grouped_xyz, grouped_features], dim=1)  # (B, 3 + C, 1, N)
            else:
                new_features = grouped_features
        else:
            new_features = grouped_xyz

        return new_features