This commit is contained in:
Haoming 2026-06-05 01:15:58 +08:00
parent 8a6f8573a3
commit 5d7b4a8bdc
4 changed files with 145 additions and 117 deletions

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@ -0,0 +1,74 @@
from functools import partial
from typing import Optional
import torch
import torch.nn as nn
import torch.nn.functional as F
class FeedForwardSwiGLU(nn.Module):
def __init__(self, dim: int, hidden_dim: int, multiple_of: int = 256, ffn_dim_multiplier: Optional[float] = None, dtype=None, device=None, operations=None):
super().__init__()
hidden_dim = int(2 * hidden_dim / 3)
# custom dim factor multiplier
if ffn_dim_multiplier is not None:
hidden_dim = int(ffn_dim_multiplier * hidden_dim)
hidden_dim = multiple_of * ((hidden_dim + multiple_of - 1) // multiple_of)
self.w1 = operations.Linear(dim, hidden_dim, bias=False, dtype=dtype, device=device)
self.w2 = operations.Linear(hidden_dim, dim, bias=False, dtype=dtype, device=device)
self.w3 = operations.Linear(dim, hidden_dim, bias=False, dtype=dtype, device=device)
def forward(self, x):
return self.w2(F.silu(self.w1(x)) * self.w3(x))
class Mlp(nn.Module):
def __init__(
self,
in_features,
hidden_features=None,
out_features=None,
act_layer=nn.GELU,
norm_layer=None,
bias=True,
drop=0.0,
use_conv=False,
dtype=None,
device=None,
operations=None,
):
super().__init__()
out_features = out_features or in_features
hidden_features = hidden_features or in_features
drop_probs = drop
linear_layer = partial(operations.Conv2d, kernel_size=1) if use_conv else operations.Linear
self.fc1 = linear_layer(in_features, hidden_features, bias=bias, dtype=dtype, device=device)
self.act = act_layer()
self.drop1 = nn.Dropout(drop_probs)
self.norm = norm_layer(hidden_features) if norm_layer is not None else nn.Identity()
self.fc2 = linear_layer(hidden_features, out_features, bias=bias, dtype=dtype, device=device)
self.drop2 = nn.Dropout(drop_probs)
def forward(self, x):
x = self.fc1(x)
x = self.act(x)
x = self.drop1(x)
x = self.norm(x)
x = self.fc2(x)
x = self.drop2(x)
return x
def get_1d_sincos_pos_embed_from_grid_torch(embed_dim, pos, device=None, dtype=torch.float32):
omega = torch.arange(embed_dim // 2, device=device, dtype=dtype)
omega /= embed_dim / 2.0
omega = 1.0 / 10000**omega # (D/2,)
pos = pos.reshape(-1) # (M,)
out = torch.einsum("m,d->md", pos, omega) # (M, D/2), outer product
emb_sin = torch.sin(out) # (M, D/2)
emb_cos = torch.cos(out) # (M, D/2)
emb = torch.cat([emb_sin, emb_cos], dim=1) # (M, D)
return emb

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@ -2,29 +2,25 @@ import torch
import torch.nn as nn
import torch.nn.functional as F
import comfy.ldm.common_dit
import comfy.patcher_extension
from comfy.ldm.flux.math import apply_rope, rope
from comfy.ldm.hidream.model import FeedForwardSwiGLU
from comfy.ldm.modules.attention import optimized_attention
from comfy.ldm.modules.diffusionmodules.mmdit import TimestepEmbedder
from backend.nn.lumina import TimestepEmbedder
from backend.utils import pad_to_patch_size
from .mmdit import FeedForwardSwiGLU
from .modules import (
FinalLayer,
PatchTokenEmbedder,
PiTBlock,
PixelTokenEmbedder,
apply_adaln_,
apply_rope,
attention_function,
precompute_freqs_cis_2d,
rope,
)
class MMDiTJointAttention(nn.Module):
"""Joint MMDiT attention with separate Q/K/V/proj for image and text streams.
RoPE is applied to each stream before concatenation so each stream uses its own
2D/1D positional encoding. Concat order is [text, image] (text first).
"""
def __init__(self, dim, num_heads=8, qkv_bias=False, dtype=None, device=None, operations=None):
super().__init__()
assert dim % num_heads == 0
@ -66,9 +62,14 @@ class MMDiTJointAttention(nn.Module):
k_joint = torch.cat([ky, kx], dim=2)
v_joint = torch.cat([vy, vx], dim=2)
out_joint = optimized_attention(
q_joint, k_joint, v_joint, H,
mask=attn_mask, skip_reshape=True, skip_output_reshape=True,
out_joint = attention_function(
q_joint,
k_joint,
v_joint,
H,
mask=attn_mask,
skip_reshape=True,
skip_output_reshape=True,
transformer_options=transformer_options,
)
@ -108,15 +109,7 @@ class MMDiTBlockT2I(nn.Module):
class PixDiT_T2I(nn.Module):
"""PixelDiT T2I model. Hardcoded for the released 1024px Stage-3 checkpoint
(also runs at 512px when fed the appropriate latent size and flow_shift).
Forward:
x: [B, 3, H, W] pixel-space input (no VAE)
timesteps:[B] in [0, 1000] (ComfyUI flow sampling convention)
context: [B, Ltxt, 2304] Gemma-2-2b-it hidden states (chi_prompt prepended)
Returns flow-matching velocity [B, 3, H, W].
"""
def __init__(
self,
in_channels=3,
@ -156,29 +149,29 @@ class PixDiT_T2I(nn.Module):
self.text_rope_theta = text_rope_theta
self.pixel_embedder = PixelTokenEmbedder(self.in_channels, self.pixel_hidden_size, dtype=dtype, device=device, operations=operations)
self.s_embedder = PatchTokenEmbedder(self.in_channels * self.patch_size ** 2, self.hidden_size, bias=True, dtype=dtype, device=device, operations=operations)
self.s_embedder = PatchTokenEmbedder(self.in_channels * self.patch_size**2, self.hidden_size, bias=True, dtype=dtype, device=device, operations=operations)
self.t_embedder = TimestepEmbedder(self.hidden_size, dtype=dtype, device=device, operations=operations, max_period=10)
self.y_embedder = PatchTokenEmbedder(self.txt_embed_dim, self.hidden_size, bias=True, use_norm=True, dtype=dtype, device=device, operations=operations)
self.y_pos_embedding = nn.Parameter(torch.empty(1, self.txt_max_length, self.hidden_size, dtype=dtype, device=device))
self.patch_blocks = nn.ModuleList([
MMDiTBlockT2I(self.hidden_size, self.num_groups,
dtype=dtype, device=device, operations=operations)
for _ in range(self.patch_depth)
])
self.pixel_blocks = nn.ModuleList([
PiTBlock(
self.pixel_hidden_size,
self.hidden_size,
patch_size=self.patch_size,
num_heads=self.num_groups,
attn_hidden_size=self.pixel_attn_hidden_size,
attn_num_heads=self.pixel_num_groups,
dtype=dtype, device=device, operations=operations,
mlp_chunks=pixel_mlp_chunks,
)
for _ in range(self.pixel_depth)
])
self.patch_blocks = nn.ModuleList([MMDiTBlockT2I(self.hidden_size, self.num_groups, dtype=dtype, device=device, operations=operations) for _ in range(self.patch_depth)])
self.pixel_blocks = nn.ModuleList(
[
PiTBlock(
self.pixel_hidden_size,
self.hidden_size,
patch_size=self.patch_size,
num_heads=self.num_groups,
attn_hidden_size=self.pixel_attn_hidden_size,
attn_num_heads=self.pixel_num_groups,
dtype=dtype,
device=device,
operations=operations,
mlp_chunks=pixel_mlp_chunks,
)
for _ in range(self.pixel_depth)
]
)
self.final_layer = FinalLayer(self.pixel_hidden_size, self.out_channels, dtype=dtype, device=device, operations=operations)
@ -188,18 +181,12 @@ class PixDiT_T2I(nn.Module):
def _fetch_text_pos(self, length, device, dtype):
return rope(torch.arange(length, dtype=torch.float32, device=device).reshape(1, -1), self.hidden_size // self.num_groups, self.text_rope_theta).squeeze(0).to(dtype=dtype)
def forward(self, x, timesteps, context=None, attention_mask=None, transformer_options={}, **kwargs):
return comfy.patcher_extension.WrapperExecutor.new_class_executor(
self._forward, self, comfy.patcher_extension.get_all_wrappers(comfy.patcher_extension.WrappersMP.DIFFUSION_MODEL, transformer_options),
).execute(x, timesteps, context, attention_mask, transformer_options, **kwargs)
def _pre_patch_block(self, s, i, **kwargs):
"""Hook for subclasses to inject per-block state into the patch stream (e.g. PiD's LQ gate)."""
return s
def _forward(self, x, timesteps, context=None, attention_mask=None, transformer_options={}, **kwargs):
def forward(self, x, timesteps, context=None, attention_mask=None, transformer_options={}, **kwargs):
H_orig, W_orig = x.shape[2], x.shape[3]
x = comfy.ldm.common_dit.pad_to_patch_size(x, (self.patch_size, self.patch_size))
x = pad_to_patch_size(x, (self.patch_size, self.patch_size))
B, _, H, W = x.shape
Hs = H // self.patch_size
Ws = W // self.patch_size
@ -215,7 +202,7 @@ class PixDiT_T2I(nn.Module):
Ltxt = min(context.shape[1], self.txt_max_length)
y = context[:, :Ltxt, :]
y_emb = self.y_embedder(y).view(B, Ltxt, self.hidden_size)
y_emb = y_emb + self.y_pos_embedding[:, :Ltxt, :].to(y_emb) # y_pos_embedding is a raw nn.Parameter
y_emb = y_emb + self.y_pos_embedding[:, :Ltxt, :].to(y_emb) # y_pos_embedding is a raw nn.Parameter
condition = F.silu(t_emb)
pos_txt = self._fetch_text_pos(Ltxt, x.device, x.dtype) if self.use_text_rope else None

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@ -1,29 +1,17 @@
import torch
import torch.nn as nn
from comfy.ldm.flux.math import apply_rope, rope
from comfy.ldm.modules.attention import optimized_attention
from comfy.ldm.modules.diffusionmodules.mmdit import Mlp, get_1d_sincos_pos_embed_from_grid_torch
from backend.attention import attention_function
from backend.nn.flux import apply_rope, rope
from .mmdit import Mlp, get_1d_sincos_pos_embed_from_grid_torch
def apply_adaln_(x, shift, scale):
return x.addcmul_(x, scale).add_(shift)
def precompute_freqs_cis_2d(dim, height, width, theta=10000.0, scale=16.0,
ref_grid_h=None, ref_grid_w=None,
scale_x=1.0, scale_y=1.0, shift_x=0.0, shift_y=0.0,
device=None, dtype=torch.float32, **kwargs):
"""2D RoPE with x/y axis frequencies interleaved at stride 2 across head dim.
rope_options:
scale_x / scale_y multiply the position range (RoPE extrapolation).
shift_x / shift_y offset the position origin (tiled / regional inference).
With ref_grid_h/w set, also applies NTK-aware per-axis theta scaling
(rope_mode='ntk_aware'): theta_axis = theta * (current/ref)^(dim_axis/(dim_axis-2)).
Returns Flux-format rotation matrices of shape [H*W, dim/2, 2, 2].
Layout of head-dim pairs: [x_0, y_0, x_1, y_1, ..., x_{dim/4-1}, y_{dim/4-1}].
"""
def precompute_freqs_cis_2d(dim, height, width, theta=10000.0, scale=16.0, ref_grid_h=None, ref_grid_w=None, scale_x=1.0, scale_y=1.0, shift_x=0.0, shift_y=0.0, device=None, dtype=torch.float32, **kwargs):
dim_axis = dim // 2
if ref_grid_h is not None and dim_axis > 2:
h_ntk = (height / ref_grid_h) ** (dim_axis / (dim_axis - 2))
@ -41,10 +29,6 @@ def precompute_freqs_cis_2d(dim, height, width, theta=10000.0, scale=16.0,
def get_2d_sincos_pos_embed(embed_dim, height, width, device=None, dtype=torch.float32):
"""Standard 2D sin/cos absolute positional embedding (ViT-style).
first half encodes W-coordinates, second half H.
"""
assert embed_dim % 4 == 0
grid_h = torch.arange(height, dtype=torch.float32, device=device)
grid_w = torch.arange(width, dtype=torch.float32, device=device)
@ -55,7 +39,7 @@ def get_2d_sincos_pos_embed(embed_dim, height, width, device=None, dtype=torch.f
class RotaryAttention(nn.Module):
"""Single-stream self-attention with rotary positional encoding (used inside PiTBlock)."""
def __init__(self, dim, num_heads=8, qkv_bias=False, dtype=None, device=None, operations=None):
super().__init__()
assert dim % num_heads == 0
@ -73,7 +57,7 @@ class RotaryAttention(nn.Module):
qkv = self.qkv(x).reshape(B, N, 3, H, D).permute(2, 0, 3, 1, 4)
q, k, v = qkv.unbind(0)
q, k = apply_rope(self.q_norm(q), self.k_norm(k), pos[None, None])
x = optimized_attention(q, k, v, H, mask=mask, skip_reshape=True, transformer_options=transformer_options)
x = attention_function(q, k, v, H, mask=mask, skip_reshape=True, transformer_options=transformer_options)
return self.proj(x)
@ -88,7 +72,7 @@ class FinalLayer(nn.Module):
class PatchTokenEmbedder(nn.Module):
"""Linear projection used both for patchified-image tokens and text-feature tokens."""
def __init__(self, in_chans, embed_dim, use_norm=False, bias=True, dtype=None, device=None, operations=None):
super().__init__()
self.proj = operations.Linear(in_chans, embed_dim, bias=bias, dtype=dtype, device=device)
@ -99,7 +83,7 @@ class PatchTokenEmbedder(nn.Module):
class PixelTokenEmbedder(nn.Module):
"""Pixel-level embedder: lifts each RGB pixel to hidden_size and packs into per-patch sequences."""
def __init__(self, in_channels, hidden_size_output, dtype=None, device=None, operations=None):
super().__init__()
self.in_channels = in_channels
@ -119,14 +103,8 @@ class PixelTokenEmbedder(nn.Module):
class PiTBlock(nn.Module):
"""Pixel-level transformer block.
Compresses each patch's P^2 pixel tokens → 1 attention token via a linear,
runs global self-attention across patches with 2D RoPE, then expands back to P^2 tokens.
Conditioning is per-pixel adaLN from the patch-level features.
"""
def __init__(self, pixel_hidden_size, patch_hidden_size, patch_size, num_heads, mlp_ratio=4.0,
attn_hidden_size=None, attn_num_heads=None, dtype=None, device=None, operations=None, mlp_chunks=1):
def __init__(self, pixel_hidden_size, patch_hidden_size, patch_size, num_heads, mlp_ratio=4.0, attn_hidden_size=None, attn_num_heads=None, dtype=None, device=None, operations=None, mlp_chunks=1):
super().__init__()
self.pixel_dim = pixel_hidden_size
self.context_dim = patch_hidden_size

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@ -1,10 +1,3 @@
"""PiD — Pixel Diffusion Decoder. Decodes a Flux/SD3/Flux2/Z-Image latent
directly to a 4x-upscaled image in 4 distilled flow-matching steps. PixDiT_T2I
body + LQ projection branch injected before each MMDiT patch block.
"""
from typing import List
import torch
import torch.nn as nn
import torch.nn.functional as F
@ -14,10 +7,6 @@ from .modules import precompute_freqs_cis_2d
class SigmaAwareGatePerTokenPerDim(nn.Module):
"""gate = sigmoid(content_proj(cat[x, lq]) - exp(log_alpha) * sigma); out = x + gate * lq.
Trained init gives ~0.88 gate at sigma=0, ~0.05 at sigma=1.
"""
def __init__(self, dim: int, dtype=None, device=None, operations=None):
super().__init__()
@ -34,7 +23,6 @@ class SigmaAwareGatePerTokenPerDim(nn.Module):
class ResBlock(nn.Module):
"""Pre-activation ResNet block: GN -> SiLU -> Conv -> GN -> SiLU -> Conv + skip."""
def __init__(self, channels: int, num_groups: int = 4, dtype=None, device=None, operations=None):
super().__init__()
@ -52,7 +40,6 @@ class ResBlock(nn.Module):
class LQProjection2D(nn.Module):
"""LQ latent -> per-block patch-aligned features for controlnet-style injection."""
def __init__(
self,
@ -65,7 +52,9 @@ class LQProjection2D(nn.Module):
num_res_blocks: int = 4,
num_outputs: int = 7,
interval: int = 2,
dtype=None, device=None, operations=None,
dtype=None,
device=None,
operations=None,
):
super().__init__()
self.latent_channels = latent_channels
@ -97,13 +86,8 @@ class LQProjection2D(nn.Module):
layers.append(ResBlock(hidden_dim, dtype=dtype, device=device, operations=operations))
self.latent_proj = nn.Sequential(*layers)
self.output_heads = nn.ModuleList(
[operations.Linear(hidden_dim, out_dim, dtype=dtype, device=device) for _ in range(num_outputs)]
)
self.gate_modules = nn.ModuleList(
[SigmaAwareGatePerTokenPerDim(out_dim, dtype=dtype, device=device, operations=operations)
for _ in range(num_outputs)]
)
self.output_heads = nn.ModuleList([operations.Linear(hidden_dim, out_dim, dtype=dtype, device=device) for _ in range(num_outputs)])
self.gate_modules = nn.ModuleList([SigmaAwareGatePerTokenPerDim(out_dim, dtype=dtype, device=device, operations=operations) for _ in range(num_outputs)])
def is_gate_active(self, block_idx: int) -> bool:
return block_idx % self.interval == 0
@ -130,7 +114,7 @@ class LQProjection2D(nn.Module):
z_aligned = z_aligned.reshape(B, z_dim * f * f, pH, pW)
return self.latent_proj(z_aligned)
def forward(self, lq_latent: torch.Tensor, target_pH: int, target_pW: int) -> List[torch.Tensor]:
def forward(self, lq_latent: torch.Tensor, target_pH: int, target_pW: int) -> list[torch.Tensor]:
feat = self._align_latent_to_patch_grid(lq_latent, target_pH, target_pW)
B, C, H, W = feat.shape
tokens = feat.permute(0, 2, 3, 1).contiguous().view(B, H * W, C)
@ -138,7 +122,6 @@ class LQProjection2D(nn.Module):
class PidNet(PixDiT_T2I):
"""PixDiT_T2I + LQ injection (one sigma-gated feature inserted before each patch block)."""
def __init__(
self,
@ -148,10 +131,12 @@ class PidNet(PixDiT_T2I):
lq_interval: int = 2,
sr_scale: int = 4,
latent_spatial_down_factor: int = 8,
rope_ref_h: int = 1024, # NTK ref resolution in PIXEL units: 1024px / patch=16 -> grid_ref=64.
rope_ref_h: int = 1024, # NTK ref resolution in PIXEL units: 1024px / patch=16 -> grid_ref=64.
rope_ref_w: int = 1024,
image_model=None,
dtype=None, device=None, operations=None,
dtype=None,
device=None,
operations=None,
**pixdit_kwargs,
):
super().__init__(dtype=dtype, device=device, operations=operations, **pixdit_kwargs)
@ -162,6 +147,7 @@ class PidNet(PixDiT_T2I):
# Parent's PiTBlocks were built with plain RoPE — swap in NTK-aware.
def _pit_rope_fn(head_dim, h, w, device=None, dtype=torch.float32, **rope_opts):
return precompute_freqs_cis_2d(head_dim, h, w, ref_grid_h=self.rope_ref_grid_h, ref_grid_w=self.rope_ref_grid_w, device=device, dtype=dtype, **rope_opts)
for blk in self.pixel_blocks:
blk._rope_fn = _pit_rope_fn
@ -184,9 +170,13 @@ class PidNet(PixDiT_T2I):
def _fetch_patch_pos(self, height, width, device, dtype, **rope_opts):
return precompute_freqs_cis_2d(
self.hidden_size // self.num_groups,
height, width,
ref_grid_h=self.rope_ref_grid_h, ref_grid_w=self.rope_ref_grid_w,
device=device, dtype=dtype, **rope_opts,
height,
width,
ref_grid_h=self.rope_ref_grid_h,
ref_grid_w=self.rope_ref_grid_w,
device=device,
dtype=dtype,
**rope_opts,
)
def _pre_patch_block(self, s, i, pid_lq_features, pid_degrade_sigma, **kwargs):
@ -197,15 +187,12 @@ class PidNet(PixDiT_T2I):
return s
return self.lq_proj.gate(s, pid_lq_features[out_idx], pid_degrade_sigma, out_idx)
def _forward(self, x, timesteps, context=None, attention_mask=None, transformer_options={}, lq_latent=None, degrade_sigma=None, **kwargs):
def forward(self, x, timesteps, context=None, attention_mask=None, transformer_options={}, lq_latent=None, degrade_sigma=None, **kwargs):
if lq_latent is None:
raise ValueError("PidNet requires lq_latent — attach via PiDConditioning")
expected_c = self.lq_proj.latent_channels
if lq_latent.shape[1] != expected_c:
raise ValueError(
f"Input latent has {lq_latent.shape[1]} channels, this model variant expects {expected_c}. "
f"Flux1/SD3 = 16 channels, Flux2 = 128 channels."
)
raise ValueError(f"Input latent has {lq_latent.shape[1]} channels, this model variant expects {expected_c}. " f"Flux1/SD3 = 16 channels, Flux2 = 128 channels.")
B = x.shape[0]
# Match the backbone's pad_to_patch_size (round up) so the LQ grid lines up with the patch stream.
Hs = -(-x.shape[2] // self.patch_size)
@ -217,9 +204,11 @@ class PidNet(PixDiT_T2I):
lq_features = self.lq_proj(lq_latent=lq_latent.to(x), target_pH=Hs, target_pW=Ws)
return super()._forward(
x, timesteps,
context=context, attention_mask=attention_mask,
return super().forward(
x,
timesteps,
context=context,
attention_mask=attention_mask,
transformer_options=transformer_options,
pid_lq_features=lq_features,
pid_degrade_sigma=degrade_sigma,