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from dataclasses import dataclass
import math
import torch
import torch.nn as nn
from einops import repeat, rearrange
from transformers import CLIPModel
import craftsman
from craftsman.models.transformers.perceiver_1d import Perceiver
from craftsman.models.transformers.attention import ResidualCrossAttentionBlock
from craftsman.utils.checkpoint import checkpoint
from craftsman.utils.base import BaseModule
from craftsman.utils.typing import *
from .utils import AutoEncoder, FourierEmbedder, get_embedder
class PerceiverCrossAttentionEncoder(nn.Module):
def __init__(self,
use_downsample: bool,
num_latents: int,
embedder: FourierEmbedder,
point_feats: int,
embed_point_feats: bool,
width: int,
heads: int,
layers: int,
init_scale: float = 0.25,
qkv_bias: bool = True,
use_ln_post: bool = False,
use_flash: bool = False,
use_checkpoint: bool = False):
super().__init__()
self.use_checkpoint = use_checkpoint
self.num_latents = num_latents
self.use_downsample = use_downsample
self.embed_point_feats = embed_point_feats
if not self.use_downsample:
self.query = nn.Parameter(torch.randn((num_latents, width)) * 0.02)
self.embedder = embedder
if self.embed_point_feats:
self.input_proj = nn.Linear(self.embedder.out_dim * 2, width)
else:
self.input_proj = nn.Linear(self.embedder.out_dim + point_feats, width)
self.cross_attn = ResidualCrossAttentionBlock(
width=width,
heads=heads,
init_scale=init_scale,
qkv_bias=qkv_bias,
use_flash=use_flash,
)
self.self_attn = Perceiver(
n_ctx=num_latents,
width=width,
layers=layers,
heads=heads,
init_scale=init_scale,
qkv_bias=qkv_bias,
use_flash=use_flash,
use_checkpoint=False
)
if use_ln_post:
self.ln_post = nn.LayerNorm(width)
else:
self.ln_post = None
def _forward(self, pc, feats):
"""
Args:
pc (torch.FloatTensor): [B, N, 3]
feats (torch.FloatTensor or None): [B, N, C]
Returns:
"""
bs, N, D = pc.shape
data = self.embedder(pc)
if feats is not None:
if self.embed_point_feats:
feats = self.embedder(feats)
data = torch.cat([data, feats], dim=-1)
data = self.input_proj(data)
if self.use_downsample:
###### fps
from torch_cluster import fps
flattened = pc.view(bs*N, D)
batch = torch.arange(bs).to(pc.device)
batch = torch.repeat_interleave(batch, N)
pos = flattened
ratio = 1.0 * self.num_latents / N
idx = fps(pos, batch, ratio=ratio)
query = data.view(bs*N, -1)[idx].view(bs, -1, data.shape[-1])
else:
query = self.query
query = repeat(query, "m c -> b m c", b=bs)
latents = self.cross_attn(query, data)
latents = self.self_attn(latents)
if self.ln_post is not None:
latents = self.ln_post(latents)
return latents
def forward(self, pc: torch.FloatTensor, feats: Optional[torch.FloatTensor] = None):
"""
Args:
pc (torch.FloatTensor): [B, N, 3]
feats (torch.FloatTensor or None): [B, N, C]
Returns:
dict
"""
return checkpoint(self._forward, (pc, feats), self.parameters(), self.use_checkpoint)
class PerceiverCrossAttentionDecoder(nn.Module):
def __init__(self,
num_latents: int,
out_dim: int,
embedder: FourierEmbedder,
width: int,
heads: int,
init_scale: float = 0.25,
qkv_bias: bool = True,
use_flash: bool = False,
use_checkpoint: bool = False):
super().__init__()
self.use_checkpoint = use_checkpoint
self.embedder = embedder
self.query_proj = nn.Linear(self.embedder.out_dim, width)
self.cross_attn_decoder = ResidualCrossAttentionBlock(
n_data=num_latents,
width=width,
heads=heads,
init_scale=init_scale,
qkv_bias=qkv_bias,
use_flash=use_flash
)
self.ln_post = nn.LayerNorm(width)
self.output_proj = nn.Linear(width, out_dim)
def _forward(self, queries: torch.FloatTensor, latents: torch.FloatTensor):
queries = self.query_proj(self.embedder(queries))
x = self.cross_attn_decoder(queries, latents)
x = self.ln_post(x)
x = self.output_proj(x)
return x
def forward(self, queries: torch.FloatTensor, latents: torch.FloatTensor):
return checkpoint(self._forward, (queries, latents), self.parameters(), self.use_checkpoint)
@craftsman.register("michelangelo-autoencoder")
class MichelangeloAutoencoder(AutoEncoder):
r"""
A VAE model for encoding shapes into latents and decoding latent representations into shapes.
"""
@dataclass
class Config(BaseModule.Config):
pretrained_model_name_or_path: str = ""
use_downsample: bool = False
num_latents: int = 256
point_feats: int = 0
embed_point_feats: bool = False
out_dim: int = 1
embed_dim: int = 64
embed_type: str = "fourier"
num_freqs: int = 8
include_pi: bool = True
width: int = 768
heads: int = 12
num_encoder_layers: int = 8
num_decoder_layers: int = 16
init_scale: float = 0.25
qkv_bias: bool = True
use_ln_post: bool = False
use_flash: bool = False
use_checkpoint: bool = True
cfg: Config
def configure(self) -> None:
super().configure()
self.embedder = get_embedder(embed_type=self.cfg.embed_type, num_freqs=self.cfg.num_freqs, include_pi=self.cfg.include_pi)
# encoder
self.cfg.init_scale = self.cfg.init_scale * math.sqrt(1.0 / self.cfg.width)
self.encoder = PerceiverCrossAttentionEncoder(
use_downsample=self.cfg.use_downsample,
embedder=self.embedder,
num_latents=self.cfg.num_latents,
point_feats=self.cfg.point_feats,
embed_point_feats=self.cfg.embed_point_feats,
width=self.cfg.width,
heads=self.cfg.heads,
layers=self.cfg.num_encoder_layers,
init_scale=self.cfg.init_scale,
qkv_bias=self.cfg.qkv_bias,
use_ln_post=self.cfg.use_ln_post,
use_flash=self.cfg.use_flash,
use_checkpoint=self.cfg.use_checkpoint
)
if self.cfg.embed_dim > 0:
# VAE embed
self.pre_kl = nn.Linear(self.cfg.width, self.cfg.embed_dim * 2)
self.post_kl = nn.Linear(self.cfg.embed_dim, self.cfg.width)
self.latent_shape = (self.cfg.num_latents, self.cfg.embed_dim)
else:
self.latent_shape = (self.cfg.num_latents, self.cfg.width)
self.transformer = Perceiver(
n_ctx=self.cfg.num_latents,
width=self.cfg.width,
layers=self.cfg.num_decoder_layers,
heads=self.cfg.heads,
init_scale=self.cfg.init_scale,
qkv_bias=self.cfg.qkv_bias,
use_flash=self.cfg.use_flash,
use_checkpoint=self.cfg.use_checkpoint
)
# decoder
self.decoder = PerceiverCrossAttentionDecoder(
embedder=self.embedder,
out_dim=self.cfg.out_dim,
num_latents=self.cfg.num_latents,
width=self.cfg.width,
heads=self.cfg.heads,
init_scale=self.cfg.init_scale,
qkv_bias=self.cfg.qkv_bias,
use_flash=self.cfg.use_flash,
use_checkpoint=self.cfg.use_checkpoint
)
if self.cfg.pretrained_model_name_or_path != "":
print(f"Loading pretrained model from {self.cfg.pretrained_model_name_or_path}")
pretrained_ckpt = torch.load(self.cfg.pretrained_model_name_or_path, map_location="cpu")
if 'state_dict' in pretrained_ckpt:
_pretrained_ckpt = {}
for k, v in pretrained_ckpt['state_dict'].items():
if k.startswith('shape_model.'):
_pretrained_ckpt[k.replace('shape_model.', '')] = v
pretrained_ckpt = _pretrained_ckpt
self.load_state_dict(pretrained_ckpt, strict=True)
def encode(self,
surface: torch.FloatTensor,
sample_posterior: bool = True):
"""
Args:
surface (torch.FloatTensor): [B, N, 3+C]
sample_posterior (bool):
Returns:
shape_latents (torch.FloatTensor): [B, num_latents, width]
kl_embed (torch.FloatTensor): [B, num_latents, embed_dim]
posterior (DiagonalGaussianDistribution or None):
"""
assert surface.shape[-1] == 3 + self.cfg.point_feats, f"\
Expected {3 + self.cfg.point_feats} channels, got {surface.shape[-1]}"
pc, feats = surface[..., :3], surface[..., 3:] # B, n_samples, 3
shape_latents = self.encoder(pc, feats) # B, num_latents, width
kl_embed, posterior = self.encode_kl_embed(shape_latents, sample_posterior) # B, num_latents, embed_dim
return shape_latents, kl_embed, posterior
def decode(self,
latents: torch.FloatTensor):
"""
Args:
latents (torch.FloatTensor): [B, embed_dim]
Returns:
latents (torch.FloatTensor): [B, embed_dim]
"""
latents = self.post_kl(latents) # [B, num_latents, embed_dim] -> [B, num_latents, width]
return self.transformer(latents)
def query(self,
queries: torch.FloatTensor,
latents: torch.FloatTensor):
"""
Args:
queries (torch.FloatTensor): [B, N, 3]
latents (torch.FloatTensor): [B, embed_dim]
Returns:
logits (torch.FloatTensor): [B, N], occupancy logits
"""
logits = self.decoder(queries, latents).squeeze(-1)
return logits
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