Files
ComfyUI/comfy/ldm/flux/model.py
comfyanonymous c308a8840a Add FluxKontextMultiReferenceLatentMethod node. (#9356)
This node is only useful if someone trains the kontext model to properly
use multiple reference images via the index method.

The default is the offset method which feeds the multiple images like if
they were stitched together as one. This method works with the current
flux kontext model.
2025-08-15 15:50:39 -04:00

253 lines
10 KiB
Python

#Original code can be found on: https://github.com/black-forest-labs/flux
from dataclasses import dataclass
import torch
from torch import Tensor, nn
from einops import rearrange, repeat
import comfy.ldm.common_dit
from .layers import (
DoubleStreamBlock,
EmbedND,
LastLayer,
MLPEmbedder,
SingleStreamBlock,
timestep_embedding,
)
@dataclass
class FluxParams:
in_channels: int
out_channels: int
vec_in_dim: int
context_in_dim: int
hidden_size: int
mlp_ratio: float
num_heads: int
depth: int
depth_single_blocks: int
axes_dim: list
theta: int
patch_size: int
qkv_bias: bool
guidance_embed: bool
class Flux(nn.Module):
"""
Transformer model for flow matching on sequences.
"""
def __init__(self, image_model=None, final_layer=True, dtype=None, device=None, operations=None, **kwargs):
super().__init__()
self.dtype = dtype
params = FluxParams(**kwargs)
self.params = params
self.patch_size = params.patch_size
self.in_channels = params.in_channels * params.patch_size * params.patch_size
self.out_channels = params.out_channels * params.patch_size * params.patch_size
if params.hidden_size % params.num_heads != 0:
raise ValueError(
f"Hidden size {params.hidden_size} must be divisible by num_heads {params.num_heads}"
)
pe_dim = params.hidden_size // params.num_heads
if sum(params.axes_dim) != pe_dim:
raise ValueError(f"Got {params.axes_dim} but expected positional dim {pe_dim}")
self.hidden_size = params.hidden_size
self.num_heads = params.num_heads
self.pe_embedder = EmbedND(dim=pe_dim, theta=params.theta, axes_dim=params.axes_dim)
self.img_in = operations.Linear(self.in_channels, self.hidden_size, bias=True, dtype=dtype, device=device)
self.time_in = MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size, dtype=dtype, device=device, operations=operations)
self.vector_in = MLPEmbedder(params.vec_in_dim, self.hidden_size, dtype=dtype, device=device, operations=operations)
self.guidance_in = (
MLPEmbedder(in_dim=256, hidden_dim=self.hidden_size, dtype=dtype, device=device, operations=operations) if params.guidance_embed else nn.Identity()
)
self.txt_in = operations.Linear(params.context_in_dim, self.hidden_size, dtype=dtype, device=device)
self.double_blocks = nn.ModuleList(
[
DoubleStreamBlock(
self.hidden_size,
self.num_heads,
mlp_ratio=params.mlp_ratio,
qkv_bias=params.qkv_bias,
dtype=dtype, device=device, operations=operations
)
for _ in range(params.depth)
]
)
self.single_blocks = nn.ModuleList(
[
SingleStreamBlock(self.hidden_size, self.num_heads, mlp_ratio=params.mlp_ratio, dtype=dtype, device=device, operations=operations)
for _ in range(params.depth_single_blocks)
]
)
if final_layer:
self.final_layer = LastLayer(self.hidden_size, 1, self.out_channels, dtype=dtype, device=device, operations=operations)
def forward_orig(
self,
img: Tensor,
img_ids: Tensor,
txt: Tensor,
txt_ids: Tensor,
timesteps: Tensor,
y: Tensor,
guidance: Tensor = None,
control = None,
transformer_options={},
attn_mask: Tensor = None,
) -> Tensor:
if y is None:
y = torch.zeros((img.shape[0], self.params.vec_in_dim), device=img.device, dtype=img.dtype)
patches_replace = transformer_options.get("patches_replace", {})
if img.ndim != 3 or txt.ndim != 3:
raise ValueError("Input img and txt tensors must have 3 dimensions.")
# running on sequences img
img = self.img_in(img)
vec = self.time_in(timestep_embedding(timesteps, 256).to(img.dtype))
if self.params.guidance_embed:
if guidance is not None:
vec = vec + self.guidance_in(timestep_embedding(guidance, 256).to(img.dtype))
vec = vec + self.vector_in(y[:,:self.params.vec_in_dim])
txt = self.txt_in(txt)
if img_ids is not None:
ids = torch.cat((txt_ids, img_ids), dim=1)
pe = self.pe_embedder(ids)
else:
pe = None
blocks_replace = patches_replace.get("dit", {})
for i, block in enumerate(self.double_blocks):
if ("double_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["img"], out["txt"] = block(img=args["img"],
txt=args["txt"],
vec=args["vec"],
pe=args["pe"],
attn_mask=args.get("attn_mask"))
return out
out = blocks_replace[("double_block", i)]({"img": img,
"txt": txt,
"vec": vec,
"pe": pe,
"attn_mask": attn_mask},
{"original_block": block_wrap})
txt = out["txt"]
img = out["img"]
else:
img, txt = block(img=img,
txt=txt,
vec=vec,
pe=pe,
attn_mask=attn_mask)
if control is not None: # Controlnet
control_i = control.get("input")
if i < len(control_i):
add = control_i[i]
if add is not None:
img += add
if img.dtype == torch.float16:
img = torch.nan_to_num(img, nan=0.0, posinf=65504, neginf=-65504)
img = torch.cat((txt, img), 1)
for i, block in enumerate(self.single_blocks):
if ("single_block", i) in blocks_replace:
def block_wrap(args):
out = {}
out["img"] = block(args["img"],
vec=args["vec"],
pe=args["pe"],
attn_mask=args.get("attn_mask"))
return out
out = blocks_replace[("single_block", i)]({"img": img,
"vec": vec,
"pe": pe,
"attn_mask": attn_mask},
{"original_block": block_wrap})
img = out["img"]
else:
img = block(img, vec=vec, pe=pe, attn_mask=attn_mask)
if control is not None: # Controlnet
control_o = control.get("output")
if i < len(control_o):
add = control_o[i]
if add is not None:
img[:, txt.shape[1] :, ...] += add
img = img[:, txt.shape[1] :, ...]
img = self.final_layer(img, vec) # (N, T, patch_size ** 2 * out_channels)
return img
def process_img(self, x, index=0, h_offset=0, w_offset=0):
bs, c, h, w = x.shape
patch_size = self.patch_size
x = comfy.ldm.common_dit.pad_to_patch_size(x, (patch_size, patch_size))
img = rearrange(x, "b c (h ph) (w pw) -> b (h w) (c ph pw)", ph=patch_size, pw=patch_size)
h_len = ((h + (patch_size // 2)) // patch_size)
w_len = ((w + (patch_size // 2)) // patch_size)
h_offset = ((h_offset + (patch_size // 2)) // patch_size)
w_offset = ((w_offset + (patch_size // 2)) // patch_size)
img_ids = torch.zeros((h_len, w_len, 3), device=x.device, dtype=x.dtype)
img_ids[:, :, 0] = img_ids[:, :, 1] + index
img_ids[:, :, 1] = img_ids[:, :, 1] + torch.linspace(h_offset, h_len - 1 + h_offset, steps=h_len, device=x.device, dtype=x.dtype).unsqueeze(1)
img_ids[:, :, 2] = img_ids[:, :, 2] + torch.linspace(w_offset, w_len - 1 + w_offset, steps=w_len, device=x.device, dtype=x.dtype).unsqueeze(0)
return img, repeat(img_ids, "h w c -> b (h w) c", b=bs)
def forward(self, x, timestep, context, y=None, guidance=None, ref_latents=None, control=None, transformer_options={}, **kwargs):
bs, c, h_orig, w_orig = x.shape
patch_size = self.patch_size
h_len = ((h_orig + (patch_size // 2)) // patch_size)
w_len = ((w_orig + (patch_size // 2)) // patch_size)
img, img_ids = self.process_img(x)
img_tokens = img.shape[1]
if ref_latents is not None:
h = 0
w = 0
index = 0
index_ref_method = kwargs.get("ref_latents_method", "offset") == "index"
for ref in ref_latents:
if index_ref_method:
index += 1
h_offset = 0
w_offset = 0
else:
index = 1
h_offset = 0
w_offset = 0
if ref.shape[-2] + h > ref.shape[-1] + w:
w_offset = w
else:
h_offset = h
h = max(h, ref.shape[-2] + h_offset)
w = max(w, ref.shape[-1] + w_offset)
kontext, kontext_ids = self.process_img(ref, index=index, h_offset=h_offset, w_offset=w_offset)
img = torch.cat([img, kontext], dim=1)
img_ids = torch.cat([img_ids, kontext_ids], dim=1)
txt_ids = torch.zeros((bs, context.shape[1], 3), device=x.device, dtype=x.dtype)
out = self.forward_orig(img, img_ids, context, txt_ids, timestep, y, guidance, control, transformer_options, attn_mask=kwargs.get("attention_mask", None))
out = out[:, :img_tokens]
return rearrange(out, "b (h w) (c ph pw) -> b c (h ph) (w pw)", h=h_len, w=w_len, ph=2, pw=2)[:,:,:h_orig,:w_orig]