Files
InvokeAI/invokeai/backend/flux/denoise.py
psychedelicious 1a1c846be3 feat(backend): include reference images in negative CFG pass for Kontext
Maintains consistency between positive and negative passes to prevent
CFG artifacts when using Kontext reference images
2025-08-04 23:03:12 +10:00

184 lines
8.4 KiB
Python

import math
from typing import Callable
import torch
from tqdm import tqdm
from invokeai.backend.flux.controlnet.controlnet_flux_output import ControlNetFluxOutput, sum_controlnet_flux_outputs
from invokeai.backend.flux.extensions.instantx_controlnet_extension import InstantXControlNetExtension
from invokeai.backend.flux.extensions.regional_prompting_extension import RegionalPromptingExtension
from invokeai.backend.flux.extensions.xlabs_controlnet_extension import XLabsControlNetExtension
from invokeai.backend.flux.extensions.xlabs_ip_adapter_extension import XLabsIPAdapterExtension
from invokeai.backend.flux.model import Flux
from invokeai.backend.rectified_flow.rectified_flow_inpaint_extension import RectifiedFlowInpaintExtension
from invokeai.backend.stable_diffusion.diffusers_pipeline import PipelineIntermediateState
def denoise(
model: Flux,
# model input
img: torch.Tensor,
img_ids: torch.Tensor,
pos_regional_prompting_extension: RegionalPromptingExtension,
neg_regional_prompting_extension: RegionalPromptingExtension | None,
# sampling parameters
timesteps: list[float],
step_callback: Callable[[PipelineIntermediateState], None],
guidance: float,
cfg_scale: list[float],
inpaint_extension: RectifiedFlowInpaintExtension | None,
controlnet_extensions: list[XLabsControlNetExtension | InstantXControlNetExtension],
pos_ip_adapter_extensions: list[XLabsIPAdapterExtension],
neg_ip_adapter_extensions: list[XLabsIPAdapterExtension],
# extra img tokens (channel-wise)
img_cond: torch.Tensor | None,
# extra img tokens (sequence-wise) - for Kontext conditioning
img_cond_seq: torch.Tensor | None = None,
img_cond_seq_ids: torch.Tensor | None = None,
):
# step 0 is the initial state
total_steps = len(timesteps) - 1
step_callback(
PipelineIntermediateState(
step=0,
order=1,
total_steps=total_steps,
timestep=int(timesteps[0]),
latents=img,
),
)
# guidance_vec is ignored for schnell.
guidance_vec = torch.full((img.shape[0],), guidance, device=img.device, dtype=img.dtype)
# Store original sequence length for slicing predictions
original_seq_len = img.shape[1]
for step_index, (t_curr, t_prev) in tqdm(list(enumerate(zip(timesteps[:-1], timesteps[1:], strict=True)))):
t_vec = torch.full((img.shape[0],), t_curr, dtype=img.dtype, device=img.device)
# Run ControlNet models.
controlnet_residuals: list[ControlNetFluxOutput] = []
for controlnet_extension in controlnet_extensions:
controlnet_residuals.append(
controlnet_extension.run_controlnet(
timestep_index=step_index,
total_num_timesteps=total_steps,
img=img,
img_ids=img_ids,
txt=pos_regional_prompting_extension.regional_text_conditioning.t5_embeddings,
txt_ids=pos_regional_prompting_extension.regional_text_conditioning.t5_txt_ids,
y=pos_regional_prompting_extension.regional_text_conditioning.clip_embeddings,
timesteps=t_vec,
guidance=guidance_vec,
)
)
# Merge the ControlNet residuals from multiple ControlNets.
# TODO(ryand): We may want to calculate the sum just-in-time to keep peak memory low. Keep in mind, that the
# controlnet_residuals datastructure is efficient in that it likely contains multiple references to the same
# tensors. Calculating the sum materializes each tensor into its own instance.
merged_controlnet_residuals = sum_controlnet_flux_outputs(controlnet_residuals)
# Prepare input for model - concatenate fresh each step
img_input = img
img_input_ids = img_ids
# Add channel-wise conditioning (for ControlNet, FLUX Fill, etc.)
if img_cond is not None:
img_input = torch.cat((img_input, img_cond), dim=-1)
# Add sequence-wise conditioning (for Kontext)
if img_cond_seq is not None:
assert img_cond_seq_ids is not None, (
"You need to provide either both or neither of the sequence conditioning"
)
img_input = torch.cat((img_input, img_cond_seq), dim=1)
img_input_ids = torch.cat((img_input_ids, img_cond_seq_ids), dim=1)
pred = model(
img=img_input,
img_ids=img_input_ids,
txt=pos_regional_prompting_extension.regional_text_conditioning.t5_embeddings,
txt_ids=pos_regional_prompting_extension.regional_text_conditioning.t5_txt_ids,
y=pos_regional_prompting_extension.regional_text_conditioning.clip_embeddings,
timesteps=t_vec,
guidance=guidance_vec,
timestep_index=step_index,
total_num_timesteps=total_steps,
controlnet_double_block_residuals=merged_controlnet_residuals.double_block_residuals,
controlnet_single_block_residuals=merged_controlnet_residuals.single_block_residuals,
ip_adapter_extensions=pos_ip_adapter_extensions,
regional_prompting_extension=pos_regional_prompting_extension,
)
# Slice prediction to only include the main image tokens
if img_cond_seq is not None:
pred = pred[:, :original_seq_len]
step_cfg_scale = cfg_scale[step_index]
# If step_cfg_scale, is 1.0, then we don't need to run the negative prediction.
if not math.isclose(step_cfg_scale, 1.0):
# TODO(ryand): Add option to run positive and negative predictions in a single batch for better performance
# on systems with sufficient VRAM.
if neg_regional_prompting_extension is None:
raise ValueError("Negative text conditioning is required when cfg_scale is not 1.0.")
# For negative prediction with Kontext, we need to include the reference images
# to maintain consistency between positive and negative passes. Without this,
# CFG would create artifacts as the attention mechanism would see different
# spatial structures in each pass
neg_img_input = img
neg_img_input_ids = img_ids
# Add channel-wise conditioning for negative pass if present
if img_cond is not None:
neg_img_input = torch.cat((neg_img_input, img_cond), dim=-1)
# Add sequence-wise conditioning (Kontext) for negative pass
# This ensures reference images are processed consistently
if img_cond_seq is not None:
neg_img_input = torch.cat((neg_img_input, img_cond_seq), dim=1)
neg_img_input_ids = torch.cat((neg_img_input_ids, img_cond_seq_ids), dim=1)
neg_pred = model(
img=neg_img_input,
img_ids=neg_img_input_ids,
txt=neg_regional_prompting_extension.regional_text_conditioning.t5_embeddings,
txt_ids=neg_regional_prompting_extension.regional_text_conditioning.t5_txt_ids,
y=neg_regional_prompting_extension.regional_text_conditioning.clip_embeddings,
timesteps=t_vec,
guidance=guidance_vec,
timestep_index=step_index,
total_num_timesteps=total_steps,
controlnet_double_block_residuals=None,
controlnet_single_block_residuals=None,
ip_adapter_extensions=neg_ip_adapter_extensions,
regional_prompting_extension=neg_regional_prompting_extension,
)
# Slice negative prediction to match main image tokens
if img_cond_seq is not None:
neg_pred = neg_pred[:, :original_seq_len]
pred = neg_pred + step_cfg_scale * (pred - neg_pred)
preview_img = img - t_curr * pred
img = img + (t_prev - t_curr) * pred
if inpaint_extension is not None:
img = inpaint_extension.merge_intermediate_latents_with_init_latents(img, t_prev)
preview_img = inpaint_extension.merge_intermediate_latents_with_init_latents(preview_img, 0.0)
step_callback(
PipelineIntermediateState(
step=step_index + 1,
order=1,
total_steps=total_steps,
timestep=int(t_curr),
latents=preview_img,
),
)
return img