2025-07-13 01:36:08 +03:00

629 lines
23 KiB
Python

import torch
from torch import Tensor
import math
import numpy as np
from skimage import measure
from dataclasses import dataclass
import torch.nn as nn
import sys, os;
sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "../../..")))
from comfy.ldm.hunyuan3d.vae import (
CrossAttentionDecoder, Transformer, ResidualCrossAttentionBlock, FourierEmbedder, VanillaVolumeDecoder
)
def fps(src: Tensor, batch: Tensor, sampling_ratio: float, start_random: bool = True):
# manually create the pointer vector
assert src.size(0) == batch.numel()
batch_size = int(batch.max()) + 1
deg = src.new_zeros(batch_size, dtype = torch.long)
deg.scatter_add_(0, batch, torch.ones_like(batch))
ptr_vec = deg.new_zeros(batch_size + 1)
torch.cumsum(deg, 0, out=ptr_vec[1:])
#return fps_sampling(src, ptr_vec, ratio)
sampled_indicies = []
for b in range(batch_size):
# start and the end of each batch
start, end = ptr_vec[b].item(), ptr_vec[b + 1].item()
# points from the point cloud
points = src[start:end]
num_points = points.size(0)
num_samples = max(1, math.ceil(num_points * sampling_ratio))
selected = torch.zeros(num_samples, device = src.device, dtype = torch.long)
distances = torch.full((num_points,), float("inf"), device = src.device)
# select a random start point
if start_random:
farthest = torch.randint(0, num_points, (1,), device = src.device)
else: farthest = torch.tensor([0], device = src.device, dtype = torch.long)
for i in range(num_samples):
selected[i] = farthest
centroid = points[farthest].squeeze(0)
dist = torch.norm(points - centroid, dim = 1) # compute euclidean distance
distances = torch.minimum(distances, dist)
farthest = torch.argmax(distances)
sampled_indicies.append(torch.arange(start, end)[selected])
return torch.cat(sampled_indicies, dim = 0)
class PointCrossAttention(nn.Module):
def __init__(self,
num_latents: int,
downsample_ratio: float,
pc_size: int,
pc_sharpedge_size: int,
point_feats: int,
width: int,
heads: int,
layers: int,
fourier_embedder,
normal_pe: bool = False,
qkv_bias: bool = False,
use_ln_post: bool = True,
qk_norm: bool = True):
super().__init__()
self.fourier_embedder = fourier_embedder
self.pc_size = pc_size
self.normal_pe = normal_pe
self.downsample_ratio = downsample_ratio
self.pc_sharpedge_size = pc_sharpedge_size
self.num_latents = num_latents
self.point_feats = point_feats
self.input_proj = nn.Linear(self.fourier_embedder.out_dim + point_feats, width)
self.cross_attn = ResidualCrossAttentionBlock(
width = width,
heads = heads,
qkv_bias = qkv_bias,
qk_norm = qk_norm
)
self.self_attn = None
if layers > 0:
self.self_attn = Transformer(
width = width,
heads = heads,
qkv_bias = qkv_bias,
qk_norm = qk_norm,
layers = layers
)
if use_ln_post:
self.ln_post = nn.LayerNorm(width)
else:
self.ln_post = None
def sample_points_and_latents(self, point_cloud: torch.Tensor, features: torch.Tensor):
"""
Subsample points randomly from the point cloud (input_pc)
Further sample the subsampled points to get query_pc
take the fourier embeddings for both input and query pc
Mental Note: FPS-sampled points (query_pc) act as latent tokens that attend to and learn from the broader context in input_pc.
Goal: get a smaller represenation (query_pc) to represent the entire scence structure by learning from a broader subset (input_pc).
More computationally efficient.
Features are additional information for each point in the cloud
"""
B, _, D = point_cloud.shape
num_latents = int(self.num_latents)
num_random_query = self.pc_size / (self.pc_size + self.pc_sharpedge_size) * num_latents
num_sharpedge_query = num_latents - num_random_query
# Split random and sharpedge surface points
random_pc, sharpedge_pc = torch.split(point_cloud, [self.pc_size, self.pc_sharpedge_size], dim=1)
# assert statements
assert random_pc.shape[1] <= self.pc_size, "Random surface points size must be less than or equal to pc_size"
assert sharpedge_pc.shape[1] <= self.pc_sharpedge_size, "Sharpedge surface points size must be less than or equal to pc_sharpedge_size"
input_random_pc_size = int(num_random_query * self.downsample_ratio)
random_query_pc, random_input_pc, random_idx_pc, random_idx_query = \
self.subsample(pc = random_pc, num_query = num_random_query, input_pc_size = input_random_pc_size)
input_sharpedge_pc_size = int(num_sharpedge_query * self.downsample_ratio)
if input_sharpedge_pc_size == 0:
sharpedge_input_pc = torch.zeros(B, 0, D, dtype = random_input_pc.dtype).to(point_cloud.device)
sharpedge_query_pc = torch.zeros(B, 0, D, dtype= random_query_pc.dtype).to(point_cloud.device)
else: sharpedge_query_pc, sharpedge_input_pc, sharpedge_idx_pc, sharpedge_idx_query = \
self.subsample(pc = sharpedge_pc, num_query = num_sharpedge_query, input_pc_size = input_sharpedge_pc_size)
# concat the random and sharpedges
query_pc = torch.cat([random_query_pc, sharpedge_query_pc], dim = 1)
input_pc = torch.cat([random_input_pc, sharpedge_input_pc], dim = 1)
query = self.fourier_embedder(query_pc)
data = self.fourier_embedder(input_pc)
if self.point_feats > 0:
random_surface_features, sharpedge_surface_features = torch.split(features, [self.pc_size, self.pc_sharpedge_size], dim = 1)
input_random_surface_features, query_random_features = \
self.handle_features(features = random_surface_features, idx_pc = random_idx_pc, batch_size = B,
input_pc_size = input_random_pc_size, idx_query = random_idx_query)
if input_sharpedge_pc_size == 0:
input_sharpedge_surface_features = torch.zeros(B, 0, self.point_feats,
dtype = input_random_surface_features.dtype, device = point_cloud.device)
query_sharpedge_features = torch.zeros(B, 0, self.point_feats,
dtype = query_random_features.dtype, device = point_cloud.device)
else:
input_sharpedge_surface_features, query_sharpedge_features = \
self.handle_features(idx_pc = sharpedge_idx_pc, features = sharpedge_surface_features,
batch_size = B, idx_query = sharpedge_idx_query, input_pc_size = input_sharpedge_pc_size)
query_features = torch.cat([query_random_features, query_sharpedge_features], dim = 1)
input_features = torch.cat([input_random_surface_features, input_sharpedge_surface_features], dim = 1)
if self.normal_pe:
# apply the fourier embeddings on the first 3 dims (xyz)
input_features_pe = self.fourier_embedder(input_features[..., :3])
query_features_pe = self.fourier_embedder(query_features[..., :3])
# replace the first 3 dims with the new PE ones
input_features = torch.cat([input_features_pe, input_features[..., :3]], dim = -1)
query_features = torch.cat([query_features_pe, query_features[..., :3]], dim = -1)
# concat at the channels dim
query = torch.cat([query, query_features], dim = -1)
data = torch.cat([data, input_features], dim = -1)
# don't return pc_info to avoid unnecessary memory usuage
return query.view(B, -1, query.shape[-1]), data.view(B, -1, data.shape[-1])
def forward(self, point_cloud: torch.Tensor, features: torch.Tensor):
query, data = self.sample_points_and_latents(point_cloud = point_cloud, features = features)
# apply projections
query = self.input_proj(query)
data = self.input_proj(data)
# apply cross attention between query and data
latents = self.cross_attn(query, data)
if self.self_attn is not None:
latents = self.self_attn(latents)
if self.ln_post is not None:
latents = self.ln_post(latents)
return latents
def subsample(self, pc, num_query, input_pc_size: int):
"""
num_query: number of points to keep after FPS
input_pc_size: number of points to select before FPS
"""
B, _, D = pc.shape
query_ratio = num_query / input_pc_size
# random subsampling of points inside the point cloud
idx_pc = torch.randperm(pc.shape[1], device = pc.device)[:input_pc_size]
input_pc = pc[:, idx_pc, :]
# flatten to allow applying fps across the whole batch
flattent_input_pc = input_pc.view(B * input_pc_size, D)
# construct a batch_down tensor to tell fps
# which points belong to which batch
N_down = int(flattent_input_pc.shape[0] / B)
batch_down = torch.arange(B).to(pc.device)
batch_down = torch.repeat_interleave(batch_down, N_down)
idx_query = fps(flattent_input_pc, batch_down, sampling_ratio = query_ratio)
query_pc = flattent_input_pc[idx_query].view(B, -1, D)
return query_pc, input_pc, idx_pc, idx_query
def handle_features(self, features, idx_pc, input_pc_size, batch_size: int, idx_query):
B = batch_size
input_surface_features = features[:, idx_pc, :]
flattent_input_features = input_surface_features.view(B * input_pc_size, -1)
query_features = flattent_input_features[idx_query].view(B, -1,
flattent_input_features.shape[-1])
return input_surface_features, query_features
def forward(self, pc, feats):
"""
Args:
pc (torch.FloatTensor): [B, N, 3]
feats (torch.FloatTensor or None): [B, N, C]
Returns:
"""
query, data = self.sample_points_and_latents(pc, feats)
query = self.input_proj(query)
query = query
data = self.input_proj(data)
data = data
latents = self.cross_attn(query, data)
if self.self_attn is not None:
latents = self.self_attn(latents)
if self.ln_post is not None:
latents = self.ln_post(latents)
return latents
@dataclass
class Latent2MeshOutput():
# mesh for vertices and faces
vertices: None
faces: None
class SurfaceExtractor():
def compute_box_stat(self, bounds, octree_resolution: int):
# if float, turn it into a cube
if isinstance(bounds, float):
bounds = [-bounds, -bounds, -bounds, bounds, bounds, bounds]
bbox_min, bbox_max = np.array(bounds[0:3]), np.array(bounds[3:6])
bbox_size = bbox_max - bbox_min
grid_size = [int(octree_resolution) + 1, int(octree_resolution) + 1, int(octree_resolution) + 1]
return grid_size, bbox_min, bbox_size
def run(self, grid_logit, *, bounds, octree_resolution, level: float = 0.0, **kwargs):
# grid_logit from volume decoder
# use marching cube algo to turn an sdf to a mesh
vertices, faces, _, _ = measure.marching_cubes(grid_logit.cpu().numpy(),
level,
method = "lewiner")
grid_size, bbox_min, bbox_size = self.compute_box_stat(bounds = bounds, octree_resolution = octree_resolution)
vertices = vertices / grid_size * bbox_size + bbox_min
return vertices, faces
def __call__(self, grid_logits, **kwds):
outputs = []
veritces_list = []
faces_list = []
# loop over the batches
for i in range(grid_logits.shape[0]):
try:
# process each batch
vertices, faces = self.run(grid_logits[i], **kwds)
vertices = vertices.astype(np.float32)
faces = np.ascontiguousarray(faces)
#outputs.append(Latent2MeshOutput(vertices = vertices, faces = faces))
veritces_list.append(vertices)
faces_list.append(faces)
except Exception:
import traceback
traceback.print_exc()
outputs.append(None)
return outputs
def normalize_mesh(mesh, scale = 0.9999):
"""Normalize mesh to fit in [-scale, scale]. Translate mesh so its center is [0,0,0]"""
bbox = mesh.bounds
center = (bbox[1] + bbox[0]) / 2
max_extent = (bbox[1] - bbox[0]).max()
mesh.apply_translation(-center)
mesh.apply_scale((2 * scale) / max_extent)
return mesh
def sample_pointcloud(mesh, num = 200000):
""" Uniformly sample points from the surface of the mesh """
points, face_idx = mesh.sample(num, return_index = True)
normals = mesh.face_normals[face_idx]
return torch.from_numpy(points.astype(np.float32)), torch.from_numpy(normals.astype(np.float32))
def detect_sharp_edges(mesh, threshold=0.985):
"""Return edge indices (a, b) that lie on sharp boundaries of the mesh."""
V, F = mesh.vertices, mesh.faces
VN, FN = mesh.vertex_normals, mesh.face_normals
sharp_mask = np.ones(V.shape[0])
for i in range(3):
indices = F[:, i]
alignment = np.einsum('ij,ij->i', VN[indices], FN)
dot_stack = np.stack((sharp_mask[indices], alignment), axis=-1)
sharp_mask[indices] = np.min(dot_stack, axis=-1)
edge_a = np.concatenate([F[:, 0], F[:, 1], F[:, 2]])
edge_b = np.concatenate([F[:, 1], F[:, 2], F[:, 0]])
sharp_edges = (sharp_mask[edge_a] < threshold) & (sharp_mask[edge_b] < threshold)
return edge_a[sharp_edges], edge_b[sharp_edges]
def sharp_sample_pointcloud(mesh, num = 16384):
""" Sample points preferentially from sharp edges in the mesh. """
edge_a, edge_b = detect_sharp_edges(mesh)
V, VN = mesh.vertices, mesh.vertex_normals
va, vb = V[edge_a], V[edge_b]
na, nb = VN[edge_a], VN[edge_b]
edge_lengths = np.linalg.norm(vb - va, axis=-1)
weights = edge_lengths / edge_lengths.sum()
indices = np.searchsorted(np.cumsum(weights), np.random.rand(num))
t = np.random.rand(num, 1)
samples = t * va[indices] + (1 - t) * vb[indices]
normals = t * na[indices] + (1 - t) * nb[indices]
return samples.astype(np.float32), normals.astype(np.float32)
def load_surface_sharpedge(mesh, num_points=4096, num_sharp_points=4096, sharpedge_flag = True, device = "cuda"):
"""Load a surface with optional sharp-edge annotations from a trimesh mesh."""
import trimesh
try:
mesh_full = trimesh.util.concatenate(mesh.dump())
except Exception:
mesh_full = trimesh.util.concatenate(mesh)
mesh_full = normalize_mesh(mesh_full)
faces = mesh_full.faces
vertices = mesh_full.vertices
origin_face_count = faces.shape[0]
mesh_surface = trimesh.Trimesh(vertices=vertices, faces=faces[:origin_face_count])
mesh_fill = trimesh.Trimesh(vertices=vertices, faces=faces[origin_face_count:])
area_surface = mesh_surface.area
area_fill = mesh_fill.area
total_area = area_surface + area_fill
sample_num = 499712 // 2
fill_ratio = area_fill / total_area if total_area > 0 else 0
num_fill = int(sample_num * fill_ratio)
num_surface = sample_num - num_fill
surf_pts, surf_normals = sample_pointcloud(mesh_surface, num_surface)
fill_pts, fill_normals = (torch.zeros(0, 3), torch.zeros(0, 3)) if num_fill == 0 else sample_pointcloud(mesh_fill, num_fill)
sharp_pts, sharp_normals = sharp_sample_pointcloud(mesh_surface, sample_num)
def assemble_tensor(points, normals, label=None):
data = torch.cat([points, normals], dim=1).half().to(device)
if label is not None:
label_tensor = torch.full((data.shape[0], 1), float(label), dtype=torch.float16).to(device)
data = torch.cat([data, label_tensor], dim=1)
return data
surface = assemble_tensor(torch.cat([surf_pts.to(device), fill_pts.to(device)], dim=0),
torch.cat([surf_normals.to(device), fill_normals.to(device)], dim=0),
label = 0 if sharpedge_flag else None)
sharp_surface = assemble_tensor(torch.from_numpy(sharp_pts), torch.from_numpy(sharp_normals),
label = 1 if sharpedge_flag else None)
rng = np.random.default_rng()
surface = surface[rng.choice(surface.shape[0], num_points, replace = False)]
sharp_surface = sharp_surface[rng.choice(sharp_surface.shape[0], num_sharp_points, replace = False)]
full = torch.cat([surface, sharp_surface], dim = 0).unsqueeze(0)
return full
class SharpEdgeSurfaceLoader:
""" Load mesh surface and sharp edge samples. """
def __init__(self, num_uniform_points = 8192, num_sharp_points = 8192):
self.num_uniform_points = num_uniform_points
self.num_sharp_points = num_sharp_points
self.total_points = num_uniform_points + num_sharp_points
def __call__(self, mesh_input, device = "cuda"):
mesh = self._load_mesh(mesh_input)
return load_surface_sharpedge(mesh, self.num_uniform_points, self.num_sharp_points, device = device)
@staticmethod
def _load_mesh(mesh_input):
import trimesh
if isinstance(mesh_input, str):
mesh = trimesh.load(mesh_input, force="mesh", merge_primitives = True)
else:
mesh = mesh_input
if isinstance(mesh, trimesh.Scene):
combined = None
for obj in mesh.geometry.values():
combined = obj if combined is None else combined + obj
return combined
return mesh
class FourierEmbedder(nn.Module):
def __init__(self, num_freq: int = 8, input_dim: int = 3, include_pi: bool = False):
super().__init__()
frequencies = 2.0 ** torch.arange(
num_freq,
dtype = torch.float32
)
if include_pi:
frequencies *= torch.pi
self.register_buffer("frequencies", frequencies, persistent = False)
self.out_dim = input_dim * (num_freq * 2 + 1)
def forward(self, x: torch.Tensor) -> torch.Tensor:
embed = (x[..., None].contiguous() * self.frequencies).view(*x.shape[:-1], -1)
return torch.cat((x, embed.sin(), embed.cos()), dim = -1)
class DiagonalGaussianDistribution:
def __init__(self, params: torch.Tensor, feature_dim: int = -1):
# divide quant channels (8) into mean and log variance
self.mean, self.logvar = torch.chunk(params, 2, dim = feature_dim)
self.logvar = torch.clamp(self.logvar, -30.0, 20.0)
self.std = torch.exp(0.5 * self.logvar)
def sample(self):
eps = torch.randn_like(self.std)
z = self.mean + eps * self.std
return z
class VAE(nn.Module):
def __init__(self,
*,
num_latents: int = 4096,
embed_dim: int = 64,
width: int = 1024,
heads: int = 16,
num_decoder_layers: int = 16,
num_encoder_layers: int = 8,
pc_size: int = 81920,
pc_sharpedge_size: int = 0,
point_feats: int = 4,
downsample_ratio: int = 20,
geo_decoder_downsample_ratio: int = 1,
geo_decoder_mlp_expand_ratio: int = 4,
geo_decoder_ln_post: bool = True,
num_frequencies: int = 8,
qkv_bias: bool = False,
qk_norm: bool = True,
drop_path_rate: float = 0.0,
include_pi: bool = False,
scale_factor: float = 1.0039506158752403
):
super().__init__()
self.latent_shape = (num_latents, embed_dim)
self.scale_factor = scale_factor
self.fourier_embedder = FourierEmbedder(num_freq = num_frequencies, include_pi = include_pi)
self.encoder = PointCrossAttention(layers = num_encoder_layers,
num_latents = num_latents,
downsample_ratio = downsample_ratio,
heads = heads,
pc_size = pc_size,
width = width,
point_feats = point_feats,
fourier_embedder = self.fourier_embedder,
pc_sharpedge_size = pc_sharpedge_size)
self.transformer = Transformer(
width=width,
layers=num_decoder_layers,
heads=heads,
qkv_bias=qkv_bias,
qk_norm=qk_norm,
drop_path_rate=drop_path_rate
)
self.geo_decoder = CrossAttentionDecoder(
fourier_embedder = self.fourier_embedder,
out_channels = 1,
mlp_expand_ratio = geo_decoder_mlp_expand_ratio,
downsample_ratio = geo_decoder_downsample_ratio,
enable_ln_post = geo_decoder_ln_post,
width=width // geo_decoder_downsample_ratio,
heads=heads // geo_decoder_downsample_ratio,
qkv_bias = qkv_bias,
qk_norm= qk_norm
)
self.pre_kl = nn.Linear(width, embed_dim * 2)
self.post_kl = nn.Linear(embed_dim, width)
self.volume_decoder = VanillaVolumeDecoder()
self.surface_extractor = SurfaceExtractor()
def forward(self):
pass
def encode(self, surface):
pc, feats = surface[:, :, :3], surface[:, :, 3:]
latents = self.encoder(pc, feats)
moments = self.pre_kl(latents)
posterior = DiagonalGaussianDistribution(moments, feature_dim = -1)
latents = posterior.sample()
return latents
def decode(self, latents, **kwargs):
to_mesh = kwargs.pop("to_mesh", True)
latents = self.post_kl(latents)
latents = self.transformer(latents)
if not to_mesh:
return latents
grid_logits = self.volume_decoder(latents = latents, geo_decoder = self.geo_decoder, **kwargs)
mesh = self.surface_extractor(grid_logits, **kwargs)
return mesh
def load_vae(vae):
DEBUG = False
checkpoint = "model.fp16.ckpt"
missing, unexpected = vae.load_state_dict(torch.load(checkpoint), strict = not DEBUG)
if DEBUG:
print(f"Missing {len(missing)}: ", missing)
print(f"\nUnexpected {len(unexpected)}: ", unexpected)
return vae