File size: 4,855 Bytes
8133633
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
9505fe5
8133633
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
9505fe5
8133633
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from dataclasses import dataclass

import torch
import torch.nn as nn
import math
import importlib
import craftsman
import re

from typing import Optional
from craftsman.utils.base import BaseModule
from craftsman.models.denoisers.utils import *

@craftsman.register("pixart-denoiser")
class PixArtDinoDenoiser(BaseModule):
    @dataclass
    class Config(BaseModule.Config):
        pretrained_model_name_or_path: Optional[str] = None
        input_channels: int = 32
        output_channels: int = 32
        n_ctx: int = 512
        width: int = 768
        layers: int = 28
        heads: int = 16
        context_dim: int = 1024
        n_views: int = 1
        context_ln: bool = True
        init_scale: float = 0.25
        use_checkpoint: bool = False
        drop_path: float = 0.
        clip_weight: float = 1.0
        dino_weight: float = 1.0

    cfg: Config

    def configure(self) -> None:
        super().configure()

        # timestep embedding
        self.time_embed = TimestepEmbedder(self.cfg.width)

        # x embedding
        self.x_embed = nn.Linear(self.cfg.input_channels, self.cfg.width, bias=True)

        # context embedding
        if self.cfg.context_ln:
            self.clip_embed = nn.Sequential(
                nn.LayerNorm(self.cfg.context_dim),
                nn.Linear(self.cfg.context_dim, self.cfg.width),
            )

            self.dino_embed = nn.Sequential(
                nn.LayerNorm(self.cfg.context_dim),
                nn.Linear(self.cfg.context_dim, self.cfg.width),
            )
        else:
            self.clip_embed = nn.Linear(self.cfg.context_dim, self.cfg.width)
            self.dino_embed = nn.Linear(self.cfg.context_dim, self.cfg.width)

        init_scale = self.cfg.init_scale * math.sqrt(1.0 / self.cfg.width)
        drop_path = [x.item() for x in torch.linspace(0, self.cfg.drop_path, self.cfg.layers)]
        self.blocks = nn.ModuleList([
            DiTBlock(
                    width=self.cfg.width, 
                    heads=self.cfg.heads, 
                    init_scale=init_scale, 
                    qkv_bias=self.cfg.drop_path, 
                    use_flash=True,
                    drop_path=drop_path[i]
            )
            for i in range(self.cfg.layers)
        ])

        self.t_block = nn.Sequential(
                        nn.SiLU(),
                        nn.Linear(self.cfg.width, 6 * self.cfg.width, bias=True)
                    )
        
         # final layer
        self.final_layer = T2IFinalLayer(self.cfg.width, self.cfg.output_channels)

        self.identity_initialize()

        if self.cfg.pretrained_model_name_or_path:
            print(f"Loading pretrained model from {self.cfg.pretrained_model_name_or_path}")
            ckpt = torch.load(self.cfg.pretrained_model_name_or_path, map_location="cpu")['state_dict']
            self.denoiser_ckpt = {}
            for k, v in ckpt.items():
                if k.startswith('denoiser_model.'):
                    self.denoiser_ckpt[k.replace('denoiser_model.', '')] = v
            self.load_state_dict(self.denoiser_ckpt, strict=False)

    def identity_initialize(self):
        for block in self.blocks:
            nn.init.constant_(block.attn.c_proj.weight, 0)
            nn.init.constant_(block.attn.c_proj.bias, 0)
            nn.init.constant_(block.cross_attn.c_proj.weight, 0)
            nn.init.constant_(block.cross_attn.c_proj.bias, 0)
            nn.init.constant_(block.mlp.c_proj.weight, 0)
            nn.init.constant_(block.mlp.c_proj.bias, 0)

    def forward(self,
                model_input: torch.FloatTensor,
                timestep: torch.LongTensor,
                context: torch.FloatTensor):

        r"""
        Args:
            model_input (torch.FloatTensor): [bs, n_data, c]
            timestep (torch.LongTensor): [bs,]
            context (torch.FloatTensor): [bs, context_tokens, c]

        Returns:
            sample (torch.FloatTensor): [bs, n_data, c]

        """

        B, n_data, _ = model_input.shape

        # 1. time
        t_emb = self.time_embed(timestep)

        # 2. conditions projector
        context = context.view(B, self.cfg.n_views, -1, self.cfg.context_dim)
        clip_feat, dino_feat = context.chunk(2, dim=2)
        clip_cond = self.clip_embed(clip_feat.contiguous().view(B, -1, self.cfg.context_dim))
        dino_cond = self.dino_embed(dino_feat.contiguous().view(B, -1, self.cfg.context_dim))
        visual_cond = self.cfg.clip_weight * clip_cond + self.cfg.dino_weight * dino_cond

        # 4. denoiser
        latent = self.x_embed(model_input)
        
        t0 = self.t_block(t_emb).unsqueeze(dim=1)
        for block in self.blocks:
            latent = auto_grad_checkpoint(block, latent, visual_cond, t0)

        latent = self.final_layer(latent, t_emb)

        return latent