File size: 8,783 Bytes
be13417
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch
import torch.nn as nn
import torch.nn.functional as F
from timm.models.layers import DropPath
from lavis.models.ulip_models.pointbert.dvae import Group
from lavis.models.ulip_models.pointbert.dvae import Encoder
from lavis.models.ulip_models.pointbert.logger import print_log

from lavis.models.ulip_models.pointbert.checkpoint import get_missing_parameters_message, get_unexpected_parameters_message

class Mlp(nn.Module):
    def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.):
        super().__init__()
        out_features = out_features or in_features
        hidden_features = hidden_features or in_features
        self.fc1 = nn.Linear(in_features, hidden_features)
        self.act = act_layer()
        self.fc2 = nn.Linear(hidden_features, out_features)
        self.drop = nn.Dropout(drop)

    def forward(self, x):
        x = self.fc1(x)
        x = self.act(x)
        x = self.drop(x)
        x = self.fc2(x)
        x = self.drop(x)
        return x


class Attention(nn.Module):
    def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0.):
        super().__init__()
        self.num_heads = num_heads
        head_dim = dim // num_heads
        # NOTE scale factor was wrong in my original version, can set manually to be compat with prev weights
        self.scale = qk_scale or head_dim ** -0.5

        self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
        self.attn_drop = nn.Dropout(attn_drop)
        self.proj = nn.Linear(dim, dim)
        self.proj_drop = nn.Dropout(proj_drop)

    def forward(self, x):
        B, N, C = x.shape
        qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads).permute(2, 0, 3, 1, 4)
        q, k, v = qkv[0], qkv[1], qkv[2]  # make torchscript happy (cannot use tensor as tuple)

        attn = (q @ k.transpose(-2, -1)) * self.scale
        attn = attn.softmax(dim=-1)
        attn = self.attn_drop(attn)

        x = (attn @ v).transpose(1, 2).reshape(B, N, C)
        x = self.proj(x)
        x = self.proj_drop(x)
        return x


class Block(nn.Module):
    def __init__(self, dim, num_heads, mlp_ratio=4., qkv_bias=False, qk_scale=None, drop=0., attn_drop=0.,
                 drop_path=0., act_layer=nn.GELU, norm_layer=nn.LayerNorm):
        super().__init__()
        self.norm1 = norm_layer(dim)

        # NOTE: drop path for stochastic depth, we shall see if this is better than dropout here
        self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
        self.norm2 = norm_layer(dim)
        mlp_hidden_dim = int(dim * mlp_ratio)
        self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)

        self.attn = Attention(
            dim, num_heads=num_heads, qkv_bias=qkv_bias, qk_scale=qk_scale, attn_drop=attn_drop, proj_drop=drop)

    def forward(self, x):
        x = x + self.drop_path(self.attn(self.norm1(x)))
        x = x + self.drop_path(self.mlp(self.norm2(x)))
        return x


class TransformerEncoder(nn.Module):
    """ Transformer Encoder without hierarchical structure
    """

    def __init__(self, embed_dim=768, depth=4, num_heads=12, mlp_ratio=4., qkv_bias=False, qk_scale=None,
                 drop_rate=0., attn_drop_rate=0., drop_path_rate=0.):
        super().__init__()

        self.blocks = nn.ModuleList([
            Block(
                dim=embed_dim, num_heads=num_heads, mlp_ratio=mlp_ratio, qkv_bias=qkv_bias, qk_scale=qk_scale,
                drop=drop_rate, attn_drop=attn_drop_rate,
                drop_path=drop_path_rate[i] if isinstance(drop_path_rate, list) else drop_path_rate
            )
            for i in range(depth)])

    def forward(self, x, pos):
        for _, block in enumerate(self.blocks):
            x = block(x + pos)
        return x


class PointTransformer(nn.Module):
    def __init__(self, config, **kwargs):
        super().__init__()
        self.config = config
        # self.args = kwargs["args"]
        self.num_features = 512
        self.trans_dim = config.trans_dim
        self.depth = config.depth
        self.drop_path_rate = config.drop_path_rate
        self.cls_dim = config.cls_dim
        self.num_heads = config.num_heads

        self.group_size = config.group_size
        self.num_group = config.num_group
        # grouper
        self.group_divider = Group(num_group=self.num_group, group_size=self.group_size)
        # define the encoder
        self.encoder_dims = config.encoder_dims
        self.encoder = Encoder(encoder_channel=self.encoder_dims)
        # bridge encoder and transformer
        self.reduce_dim = nn.Linear(self.encoder_dims, self.trans_dim)

        self.cls_token = nn.Parameter(torch.zeros(1, 1, self.trans_dim))
        self.cls_pos = nn.Parameter(torch.randn(1, 1, self.trans_dim))

        self.pos_embed = nn.Sequential(
            nn.Linear(3, 128),
            nn.GELU(),
            nn.Linear(128, self.trans_dim)
        )

        dpr = [x.item() for x in torch.linspace(0, self.drop_path_rate, self.depth)]
        self.blocks = TransformerEncoder(
            embed_dim=self.trans_dim,
            depth=self.depth,
            drop_path_rate=dpr,
            num_heads=self.num_heads
        )

        self.norm = nn.LayerNorm(self.trans_dim)
        # self.load_model_from_ckpt('/export/home/repos/SLIP/pretrained_models/point_transformer_8192.pt')
        # if not self.args.evaluate_3d:
        ## TODO: pass as config
        # self.load_model_from_ckpt('/export/home/ULIP/data/initialize_models/ULIP-2_pointbert_last.pt')

        # self.cls_head_finetune = nn.Sequential(
        #     nn.Linear(self.trans_dim * 2, 256),
        #     nn.ReLU(inplace=True),
        #     nn.Dropout(0.5),
        #     nn.Linear(256, self.cls_dim)
        # )

        # self.build_loss_func()

    def build_loss_func(self):
        self.loss_ce = nn.CrossEntropyLoss()

    def get_loss_acc(self, pred, gt, smoothing=True):
        # import pdb; pdb.set_trace()
        gt = gt.contiguous().view(-1).long()

        if smoothing:
            eps = 0.2
            n_class = pred.size(1)

            one_hot = torch.zeros_like(pred).scatter(1, gt.view(-1, 1), 1)
            one_hot = one_hot * (1 - eps) + (1 - one_hot) * eps / (n_class - 1)
            log_prb = F.log_softmax(pred, dim=1)

            loss = -(one_hot * log_prb).sum(dim=1).mean()
        else:
            loss = self.loss_ce(pred, gt.long())

        pred = pred.argmax(-1)
        acc = (pred == gt).sum() / float(gt.size(0))

        return loss, acc * 100

    def load_model_from_ckpt(self, bert_ckpt_path):
        ckpt = torch.load(bert_ckpt_path, map_location='cpu')
        base_ckpt = {k.replace("module.", ""): v for k, v in ckpt['state_dict'].items()}
        for k in list(base_ckpt.keys()):
            if k.startswith('transformer_q') and not k.startswith('transformer_q.cls_head'):
                base_ckpt[k[len('transformer_q.'):]] = base_ckpt[k]
            elif k.startswith('base_model'):
                base_ckpt[k[len('base_model.'):]] = base_ckpt[k]
            del base_ckpt[k]

        incompatible = self.load_state_dict(base_ckpt, strict=True)

        if incompatible.missing_keys:
            print_log('missing_keys', logger='Transformer')
            print_log(
                get_missing_parameters_message(incompatible.missing_keys),
                logger='Transformer'
            )
        if incompatible.unexpected_keys:
            print_log('unexpected_keys', logger='Transformer')
            print_log(
                get_unexpected_parameters_message(incompatible.unexpected_keys),
                logger='Transformer'
            )

        print_log(f'[Transformer] Successful Loading the ckpt from {bert_ckpt_path}', logger='Transformer')

    def forward(self, pts):
        # divide the point cloud in the same form. This is important
        neighborhood, center = self.group_divider(pts)
        # encoder the input cloud blocks
        group_input_tokens = self.encoder(neighborhood)  # B G N
        group_input_tokens = self.reduce_dim(group_input_tokens)
        # prepare cls
        cls_tokens = self.cls_token.expand(group_input_tokens.size(0), -1, -1)
        cls_pos = self.cls_pos.expand(group_input_tokens.size(0), -1, -1)
        # add pos embedding
        pos = self.pos_embed(center)
        # final input
        x = torch.cat((cls_tokens, group_input_tokens), dim=1)
        pos = torch.cat((cls_pos, pos), dim=1)
        # transformer
        x = self.blocks(x, pos)
        x = self.norm(x)
        concat_f = torch.cat([x[:, 0], x[:, 1:].max(1)[0]], dim=-1)
        # ret = self.cls_head_finetune(concat_f)
        return concat_f