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358 lines
11 KiB
358 lines
11 KiB
import math
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from dataclasses import dataclass
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from typing import Dict, Optional, Tuple, Union
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class ResConvBlock(nn.Module):
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"""残差卷积块"""
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def __init__(self, in_channels: int, mid_channels: int, out_channels: int):
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super().__init__()
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self.conv1 = nn.Conv1d(in_channels, mid_channels, 3, padding=1)
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self.norm1 = nn.GroupNorm(32, mid_channels)
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self.conv2 = nn.Conv1d(mid_channels, out_channels, 3, padding=1)
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self.norm2 = nn.GroupNorm(32, out_channels)
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self.act = nn.SiLU()
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self.conv_shortcut = None
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if in_channels != out_channels:
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self.conv_shortcut = nn.Conv1d(in_channels, out_channels, 1)
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def forward(self, x):
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residual = x
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x = self.conv1(x)
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x = self.norm1(x)
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x = self.act(x)
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x = self.conv2(x)
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x = self.norm2(x)
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if self.conv_shortcut is not None:
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residual = self.conv_shortcut(residual)
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return self.act(x + residual)
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class SelfAttention1d(nn.Module):
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"""一维自注意力层"""
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def __init__(self, channels: int, num_head_channels: int):
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super().__init__()
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self.num_heads = channels // num_head_channels
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self.scale = num_head_channels ** -0.5
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self.qkv = nn.Conv1d(channels, channels * 3, 1)
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self.proj = nn.Conv1d(channels, channels, 1)
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def forward(self, x):
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b, c, l = x.shape
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qkv = self.qkv(x).reshape(b, 3, self.num_heads, c // self.num_heads, l)
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q, k, v = qkv.unbind(1)
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attn = (q @ k.transpose(-2, -1)) * self.scale
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attn = attn.softmax(dim=-1)
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x = (attn @ v).reshape(b, c, l)
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x = self.proj(x)
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return x
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class UNetMidBlock1D(nn.Module):
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"""U-Net中间块"""
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def __init__(self, in_channels: int, mid_channels: int):
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super().__init__()
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self.resnets = nn.ModuleList([
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ResConvBlock(in_channels, mid_channels, mid_channels),
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ResConvBlock(mid_channels, mid_channels, mid_channels),
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ResConvBlock(mid_channels, mid_channels, in_channels),
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])
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self.attentions = nn.ModuleList([
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SelfAttention1d(mid_channels, mid_channels // 32)
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for _ in range(3)
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])
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def forward(self, x):
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for attn, resnet in zip(self.attentions, self.resnets):
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x = resnet(x)
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x = attn(x)
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return x
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class Encoder1D(nn.Module):
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"""一维编码器"""
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def __init__(
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self,
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in_channels: int = 3,
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out_channels: int = 256,
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block_out_channels: Tuple[int] = (64, 128, 256),
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layers_per_block: int = 2,
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):
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super().__init__()
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self.conv_in = nn.Conv1d(in_channels, block_out_channels[0], 3, padding=1)
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self.down_blocks = nn.ModuleList([])
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in_ch = block_out_channels[0]
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for out_ch in block_out_channels:
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block = []
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for _ in range(layers_per_block):
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block.append(ResConvBlock(in_ch, out_ch, out_ch))
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in_ch = out_ch
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if out_ch != block_out_channels[-1]:
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block.append(nn.AvgPool1d(2))
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self.down_blocks.append(nn.Sequential(*block))
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self.mid_block = UNetMidBlock1D(
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in_channels=block_out_channels[-1],
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mid_channels=block_out_channels[-1],
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)
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self.conv_out = nn.Sequential(
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nn.GroupNorm(32, block_out_channels[-1]),
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nn.SiLU(),
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nn.Conv1d(block_out_channels[-1], out_channels, 3, padding=1),
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)
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def forward(self, x):
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x = self.conv_in(x)
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for block in self.down_blocks:
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x = block(x)
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x = self.mid_block(x)
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x = self.conv_out(x)
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return x
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class BRepFeatureEmbedder(nn.Module):
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"""B-rep特征嵌入器"""
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def __init__(self, use_cf: bool = True):
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super().__init__()
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self.embed_dim = 768
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self.use_cf = use_cf
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layer = nn.TransformerEncoderLayer(
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d_model=self.embed_dim,
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nhead=12,
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norm_first=False,
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dim_feedforward=1024,
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dropout=0.1
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)
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self.transformer = nn.TransformerEncoder(
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layer,
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num_layers=12,
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norm=nn.LayerNorm(self.embed_dim),
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enable_nested_tensor=False # 添加这个参数
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)
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self.surfz_embed = nn.Sequential(
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nn.Linear(3*16, self.embed_dim),
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nn.LayerNorm(self.embed_dim),
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nn.SiLU(),
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nn.Linear(self.embed_dim, self.embed_dim),
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)
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self.edgez_embed = nn.Sequential(
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nn.Linear(3*4, self.embed_dim),
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nn.LayerNorm(self.embed_dim),
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nn.SiLU(),
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nn.Linear(self.embed_dim, self.embed_dim),
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)
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self.surfp_embed = nn.Sequential(
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nn.Linear(6, self.embed_dim),
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nn.LayerNorm(self.embed_dim),
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nn.SiLU(),
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nn.Linear(self.embed_dim, self.embed_dim),
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)
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self.edgep_embed = nn.Sequential(
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nn.Linear(6, self.embed_dim),
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nn.LayerNorm(self.embed_dim),
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nn.SiLU(),
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nn.Linear(self.embed_dim, self.embed_dim),
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)
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self.vertp_embed = nn.Sequential(
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nn.Linear(6, self.embed_dim),
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nn.LayerNorm(self.embed_dim),
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nn.SiLU(),
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nn.Linear(self.embed_dim, self.embed_dim),
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)
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def forward(self, surf_z, edge_z, surf_p, edge_p, vert_p, mask=None):
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# 特征嵌入
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surf_embeds = self.surfz_embed(surf_z)
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edge_embeds = self.edgez_embed(edge_z)
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# 点嵌入
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surf_p_embeds = self.surfp_embed(surf_p)
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edge_p_embeds = self.edgep_embed(edge_p)
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vert_p_embeds = self.vertp_embed(vert_p)
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# 组合所有嵌入
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if self.use_cf:
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embeds = torch.cat([
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surf_embeds + surf_p_embeds,
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edge_embeds + edge_p_embeds,
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vert_p_embeds
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], dim=1)
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else:
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embeds = torch.cat([
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surf_p_embeds,
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edge_p_embeds,
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vert_p_embeds
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], dim=1)
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output = self.transformer(embeds, src_key_padding_mask=mask)
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return output
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class SDFTransformer(nn.Module):
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"""SDF Transformer编码器"""
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def __init__(self, embed_dim: int = 768, num_layers: int = 6):
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super().__init__()
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layer = nn.TransformerEncoderLayer(
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d_model=embed_dim,
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nhead=8,
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dim_feedforward=1024,
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dropout=0.1,
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batch_first=True,
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norm_first=False # 修改这里:设置为False
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)
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self.transformer = nn.TransformerEncoder(layer, num_layers)
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def forward(self, x, mask=None):
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return self.transformer(x, src_key_padding_mask=mask)
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class SDFHead(nn.Module):
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"""SDF预测头"""
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def __init__(self, embed_dim: int = 768*2):
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super().__init__()
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self.mlp = nn.Sequential(
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nn.Linear(embed_dim, embed_dim//2),
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nn.LayerNorm(embed_dim//2),
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nn.ReLU(),
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nn.Linear(embed_dim//2, embed_dim//4),
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nn.LayerNorm(embed_dim//4),
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nn.ReLU(),
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nn.Linear(embed_dim//4, 1),
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nn.Tanh()
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)
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def forward(self, x):
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return self.mlp(x)
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class BRepToSDF(nn.Module):
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def __init__(
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self,
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brep_feature_dim: int = 48,
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use_cf: bool = True,
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embed_dim: int = 768,
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latent_dim: int = 256
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):
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super().__init__()
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self.embed_dim = embed_dim
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# 1. 查询点编码器
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self.query_encoder = nn.Sequential(
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nn.Linear(3, embed_dim//4),
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nn.LayerNorm(embed_dim//4),
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nn.ReLU(),
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nn.Linear(embed_dim//4, embed_dim//2),
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nn.LayerNorm(embed_dim//2),
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nn.ReLU(),
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nn.Linear(embed_dim//2, embed_dim)
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)
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# 2. B-rep特征编码器
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self.feature_embedder = BRepFeatureEmbedder(use_cf=use_cf)
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# 3. 特征融合Transformer
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self.transformer = SDFTransformer(
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embed_dim=embed_dim,
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num_layers=6
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)
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# 4. SDF预测头
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self.sdf_head = SDFHead(embed_dim=embed_dim*2)
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def forward(self, surf_z, edge_z, surf_p, edge_p, vert_p, query_points, mask=None):
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"""
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Args:
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surf_z: 表面特征 [B, N, 48]
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edge_z: 边特征 [B, M, 12]
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surf_p: 表面点 [B, N, 6]
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edge_p: 边点 [B, M, 6]
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vert_p: 顶点点 [B, K, 6]
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query_points: 查询点 [B, Q, 3]
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mask: 注意力掩码
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Returns:
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sdf: [B, Q, 1]
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"""
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B, Q, _ = query_points.shape
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# 1. B-rep特征嵌入
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brep_features = self.feature_embedder(
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surf_z, edge_z, surf_p, edge_p, vert_p, mask
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) # [B, N+M+K, embed_dim]
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# 2. 查询点编码
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query_features = self.query_encoder(query_points) # [B, Q, embed_dim]
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# 3. 提取全局特征
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global_features = brep_features.mean(dim=1) # [B, embed_dim]
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# 4. 为每个查询点准备特征
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expanded_features = global_features.unsqueeze(1).expand(-1, Q, -1) # [B, Q, embed_dim]
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# 5. 连接查询点特征和全局特征
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combined_features = torch.cat([
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expanded_features, # [B, Q, embed_dim]
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query_features # [B, Q, embed_dim]
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], dim=-1) # [B, Q, embed_dim*2]
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# 6. SDF预测
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sdf = self.sdf_head(combined_features) # [B, Q, 1]
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return sdf
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def sdf_loss(pred_sdf, gt_sdf, points, grad_weight: float = 0.1):
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"""SDF损失函数"""
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# L1损失
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l1_loss = F.l1_loss(pred_sdf, gt_sdf)
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# 梯度约束损失
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grad = torch.autograd.grad(
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pred_sdf.sum(),
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points,
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create_graph=True
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)[0]
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grad_constraint = F.mse_loss(
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torch.norm(grad, dim=-1),
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torch.ones_like(pred_sdf.squeeze(-1))
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)
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return l1_loss + grad_weight * grad_constraint
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def main():
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# 初始化模型
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model = BRepToSDF(
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brep_feature_dim=48,
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use_cf=True,
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embed_dim=768,
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latent_dim=256
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)
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# 示例输入
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batch_size = 4
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num_surfs = 10
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num_edges = 20
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num_verts = 8
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num_queries = 1000
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# 生成示例数据
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surf_z = torch.randn(batch_size, num_surfs, 48)
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edge_z = torch.randn(batch_size, num_edges, 12)
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surf_p = torch.randn(batch_size, num_surfs, 6)
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edge_p = torch.randn(batch_size, num_edges, 6)
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vert_p = torch.randn(batch_size, num_verts, 6)
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query_points = torch.randn(batch_size, num_queries, 3)
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# 前向传播
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sdf = model(surf_z, edge_z, surf_p, edge_p, vert_p, query_points)
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print(f"Output SDF shape: {sdf.shape}")
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if __name__ == "__main__":
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main()
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