Skip to content

Conversation

@Pfannkuchensack
Copy link
Contributor

@Pfannkuchensack Pfannkuchensack commented Dec 4, 2025

Summary

This PR adds Regional Guidance support for Z-Image (S3-DiT Transformer) models, enabling users to apply different prompts to different regions of the image using attention masks.

Key implementation details:

Backend:

  • New ZImageRegionalPromptingExtension class that builds regional attention masks
  • New ZImageTextConditioning and ZImageRegionalTextConditioning dataclasses for managing regional text embeddings
  • Transformer forward patching via patch_transformer_for_regional_prompting context manager
  • Attention mask format: 4D additive float mask (0.0 = attend, -inf = block) in bfloat16 dtype
  • Alternating layer strategy: even layers use regional mask, odd layers use full attention for global coherence
  • Z-Image uses sequence order [img_tokens, txt_tokens] (different from FLUX's [txt_tokens, img_tokens])

Frontend:

  • Updated buildZImageGraph.ts to support regional conditioning collectors
  • Updated addRegions.ts to create z_image_text_encoder nodes for Z-Image regions
  • Updated addZImageLoRAs.ts to handle optional negCond when guidance_scale=0
  • Added Z-Image validation in validators.ts (no IP adapters, no autoNegative support)
  • Negative conditioning nodes only created when guidance_scale > 0

Related Issues / Discussions

#8670
Extends Z-Image support (from the Z-Image-Turbo PR) with regional prompting capabilities.

QA Instructions

  1. Select a Z-Image model (e.g., Z-Image-Turbo)
  2. Create two or more Regional Guidance layers in the Control Layers panel
  3. Draw masks for each region
  4. Add different prompts to each region (e.g., "red apple" for left region, "blue sky" for right region)
  5. Add a global prompt (optional)
  6. Generate image
  7. Verify that different regions follow their respective prompts

Merge Plan

Should be merged after the main Z-Image support PR (feat/z-image-turbo-support), as this builds on top of that implementation.

Checklist

  • The PR has a short but descriptive title, suitable for a changelog
  • Tests added / updated (if applicable)
  • ❗Changes to a redux slice have a corresponding migration
  • Documentation added / updated (if applicable)
  • Updated What's New copy (if doing a release after this PR)

Pfannkuchensack and others added 10 commits December 1, 2025 00:22
Add comprehensive support for Z-Image-Turbo (S3-DiT) models including:

Backend:
- New BaseModelType.ZImage in taxonomy
- Z-Image model config classes (ZImageTransformerConfig, Qwen3TextEncoderConfig)
- Model loader for Z-Image transformer and Qwen3 text encoder
- Z-Image conditioning data structures
- Step callback support for Z-Image with FLUX latent RGB factors

Invocations:
- z_image_model_loader: Load Z-Image transformer and Qwen3 encoder
- z_image_text_encoder: Encode prompts using Qwen3 with chat template
- z_image_denoise: Flow matching denoising with time-shifted sigmas
- z_image_image_to_latents: Encode images to 16-channel latents
- z_image_latents_to_image: Decode latents using FLUX VAE

Frontend:
- Z-Image graph builder for text-to-image generation
- Model picker and validation updates for z-image base type
- CFG scale now allows 0 (required for Z-Image-Turbo)
- Clip skip disabled for Z-Image (uses Qwen3, not CLIP)
- Optimal dimension settings for Z-Image (1024x1024)

Technical details:
- Uses Qwen3 text encoder (not CLIP/T5)
- 16 latent channels with FLUX-compatible VAE
- Flow matching scheduler with dynamic time shift
- 8 inference steps recommended for Turbo variant
- bfloat16 inference dtype
Add comprehensive LoRA support for Z-Image models including:

Backend:
- New Z-Image LoRA config classes (LoRA_LyCORIS_ZImage_Config, LoRA_Diffusers_ZImage_Config)
- Z-Image LoRA conversion utilities with key mapping for transformer and Qwen3 encoder
- LoRA prefix constants (Z_IMAGE_LORA_TRANSFORMER_PREFIX, Z_IMAGE_LORA_QWEN3_PREFIX)
- LoRA detection logic to distinguish Z-Image from Flux models
- Layer patcher improvements for proper dtype conversion and parameter
…ntification

Move Flux layer structure check before metadata check to prevent misidentifying Z-Image LoRAs (which use `diffusion_model.layers.X`) as Flux AI Toolkit format. Flux models use `double_blocks` and `single_blocks` patterns which are now checked first regardless of metadata presence.
…ibility

Add comprehensive support for GGUF quantized Z-Image models and improve component flexibility:

Backend:
- New Main_GGUF_ZImage_Config for GGUF quantized Z-Image transformers
- Z-Image key detection (_has_z_image_keys) to identify S3-DiT models
- GGUF quantization detection and sidecar LoRA patching for quantized models
- Qwen3Encoder_Qwen3Encoder_Config for standalone Qwen3 encoder models

Model Loader:
- Split Z-Image model
Implements regional prompting for Z-Image (S3-DiT Transformer) allowing
different prompts to affect different image regions using attention masks.

Backend changes:
- Add ZImageRegionalPromptingExtension for mask preparation
- Add ZImageTextConditioning and ZImageRegionalTextConditioning data classes
- Patch transformer forward to inject 4D regional attention masks
- Use additive float mask (0.0 attend, -inf block) in bfloat16 for compatibility
- Alternate regional/full attention layers for global coherence

Frontend changes:
- Update buildZImageGraph to support regional conditioning collectors
- Update addRegions to create z_image_text_encoder nodes for regions
- Update addZImageLoRAs to handle optional negCond when guidance_scale=0
- Add Z-Image validation (no IP adapters, no autoNegative)
@github-actions github-actions bot added api python PRs that change python files Root invocations PRs that change invocations backend PRs that change backend files frontend PRs that change frontend files python-deps PRs that change python dependencies labels Dec 4, 2025
Fix windows path again
Add support for loading Z-Image transformer and Qwen3 encoder models
from single-file safetensors format (in addition to existing diffusers
directory format).

Changes:
- Add Main_Checkpoint_ZImage_Config and Main_GGUF_ZImage_Config for
  single-file Z-Image transformer models
- Add Qwen3Encoder_Checkpoint_Config for single-file Qwen3 text encoder
- Add ZImageCheckpointModel and ZImageGGUFCheckpointModel loaders with
  automatic key conversion from original to diffusers format
- Add Qwen3EncoderCheckpointLoader using Qwen3ForCausalLM with fast
  loading via init_empty_weights and proper weight tying for lm_head
- Update z_image_denoise to accept Checkpoint format models
Add support for saving and recalling Z-Image component models (VAE and
Qwen3 Encoder) in image metadata.

Backend:
- Add qwen3_encoder field to CoreMetadataInvocation (version 2.1.0)

Frontend:
- Add vae and qwen3_encoder to Z-Image graph metadata
- Add Qwen3EncoderModel metadata handler for recall
- Add ZImageVAEModel metadata handler (uses zImageVaeModelSelected
  instead of vaeSelected to set Z-Image-specific VAE state)
- Add qwen3Encoder translation key

This enables "Recall Parameters" / "Remix Image" to restore the VAE
and Qwen3 Encoder settings used for Z-Image generations.
Add robust device capability detection for bfloat16, replacing hardcoded
dtype with runtime checks that fallback to float16/float32 on unsupported
hardware. This prevents runtime failures on GPUs and CPUs without bfloat16.

Key changes:
- Add TorchDevice.choose_bfloat16_safe_dtype() helper for safe dtype selection
- Fix LoRA device mismatch in layer_patcher.py (add device= to .to() call)
- Replace all assert statements with descriptive exceptions (TypeError/ValueError)
- Add hidden_states bounds check and apply_chat_template fallback in text encoder
- Add GGUF QKV tensor validation (divisible by 3 check)
- Fix CPU noise generation to use float32 for compatibility
- Remove verbose debug logging from LoRA conversion utils
…inModelConfig

The FLUX Dev license warning in model pickers used isCheckpointMainModelConfig
incorrectly:
```
isCheckpointMainModelConfig(config) && config.variant === 'dev'
```

This caused a TypeScript error because CheckpointModelConfig type doesn't
include the 'variant' property (it's extracted as `{ type: 'main'; format:
'checkpoint' }` which doesn't narrow to include variant).

Changes:
- Add isFluxDevMainModelConfig type guard that properly checks
  base='flux' AND variant='dev', returning MainModelConfig
- Update MainModelPicker and InitialStateMainModelPicker to use new guard
- Remove isCheckpointMainModelConfig as it had no other usages

The function was removed because:
1. It was only used for detecting FLUX Dev models (incorrect use case)
2. No other code needs a generic "is checkpoint format" check
3. The pattern in this codebase is specific type guards per model variant
   (isFluxFillMainModelModelConfig, isRefinerMainModelModelConfig, etc.)
…ters

- Add Qwen3EncoderGGUFLoader for llama.cpp GGUF quantized text encoders
- Convert llama.cpp key format (blk.X., token_embd) to PyTorch format
- Handle tied embeddings (lm_head.weight ↔ embed_tokens.weight)
- Dequantize embed_tokens for embedding lookups (GGMLTensor limitation)
- Add QK normalization key mappings (q_norm, k_norm) for Qwen3
- Set Z-Image defaults: steps=9, cfg_scale=0.0, width/height=1024
- Allow cfg_scale >= 0 (was >= 1) for Z-Image Turbo compatibility
- Add GGUF format detection for Qwen3 model probing
…rNorm

- Add CustomDiffusersRMSNorm for diffusers.models.normalization.RMSNorm
- Add CustomLayerNorm for torch.nn.LayerNorm
- Register both in AUTOCAST_MODULE_TYPE_MAPPING

Enables partial loading (enable_partial_loading: true) for Z-Image models
by wrapping their normalization layers with device autocast support
@lstein
Copy link
Collaborator

lstein commented Dec 16, 2025

I will start my review after the base z-image-turbo support is merged, which should be soon.

…noise node

The Z-Image denoise node outputs latents, not images, so these mixins
were unnecessary. Metadata and board handling is correctly done in the
L2I (latents-to-image) node. This aligns with how FLUX denoise works.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

api backend PRs that change backend files frontend PRs that change frontend files invocations PRs that change invocations python PRs that change python files python-deps PRs that change python dependencies Root

Projects

None yet

Development

Successfully merging this pull request may close these issues.

3 participants