V3.5.1 Emergency Compatibility Hotfix

Reference Audio sockets are now permanently defined by Python INPUT_TYPES. Dynamic socket changes and the UI-only Hidden / Show control were removed to prevent workflow save/reload value shifts.

Node IDs, backend keys, Sampling, Conditioning, Seed handling, and other widgets are unchanged.

MiniMax H3 Continuum

> v3.5.1 Update

This update improves the Second Pass workflow, reference handling, and seed behavior. It adds the new Conditioning Bridge V3.5 for external sampling workflows, optional Reference Audio conditioning, and improved Last Queued Seed Reuse.

When using ComfyUI's Randomize seed mode, Continuum now remembers the seed that was actually queued. If you like the First Pass result and switch the seed control to Fixed, Continuum can restore that seed so the existing First Pass can be reused for the Second Pass when it is still available in cache, instead of unnecessarily generating a different First Pass.

Video reference inputs are also clarified as Video Guide Frames / Video Guide Size, while existing V3.4/V3.5 workflows and backend connections remain compatible.

Updating to V3.5 does not automatically replace V3.4 nodes in saved workflows. When updating an older workflow, replace not only the Sampler but also the assembler with H3 Continuum Assemble + Seam V3.5. Add H3 Continuum Hi-Res Fix V3.5 when Hi-Res Fix is required.

GitHub:
https://github.com/ukr8b3g-cmyk/ComfyUI-H3-Continuum

[ V3.5 ]

V3.5 introduces two major additions:

- Continuum-aware Second Pass / Hi-Res Fix

Refine externally processed H3 latents while preserving Continuum physical groups, prompts, seeds, ordering, and first-pass audio. An integrated one-node 2x Hi-Res Fix path is also included as an experimental feature.

- Low-memory Assemble + Seam V3.5

Adds Auto, RAM, and Disk-backed video-buffer modes. Disk-backed assembly significantly reduces system RAM/private-memory usage for long or high-resolution outputs while preserving Exact Duration, Seam, Terminal Merge, and audio behavior.

All V3.4 nodes remain available for saved-workflow compatibility. Existing V3.4 workflows continue to work unchanged.

The V3.5 release passed 430 automated tests and representative GPU acceptance tests.

Note: The integrated Hi-Res Fix remains experimental. Long 2x workflows can require substantial GPU VRAM.

#5 3 chunks x 15 seconds

#6 6 chunks x 15 seconds

W576xH576

[ v3.4 ]

Long-form MiniMax H3 video and audio generation for ComfyUI with chunked generation, persistent references, restartable runs, and user-controlled audio.

### What's new in v3.4

- Driving Audio: preserves the supplied audio as the final audio while guiding generation across chunks.

- Video Reference: provides persistent visual reference for identity, motion, framing, and scene appearance.

- Restartable chunks: reuse completed chunks with Run Storage and regenerate only the required part.

- Improved Core compatibility: unknown upstream or custom nodes are not rejected merely because they are not recognized by Continuum.

- Simpler stable interface: obsolete compatibility controls and experimental Timeline inputs are hidden from the V3.4 public workflow.

- Spectrum interoperability: Spectrum remains optional and can use the official H3 Continuum Interop API.

### Direction change from v3.3

V3.4 focuses on predictable reference workflows rather than experimental Timeline Video and timeline-audio generation.

Driving Audio preserves the original user-supplied audio. Video Reference provides persistent visual guidance without requiring exact frame-by-frame copying. Existing V3.3 workflows remain available through legacy compatibility paths.

### Updating

For an existing Git installation:

git pull --ff-only origin main

V3.4 input connection patterns

V3.4 separates the visual reference input from the driving-audio input. Choose the connection pattern that matches your source material.

1. Audio only

Connect Load Audio to driving_audio. Use this when an existing song, dialogue track, or sound effect should remain the final audio. A Video Reference is not required.

2. Video with its own audio

Connect Load Video (Upload) IMAGE to Video Reference. If the uploaded video contains the audio you want to preserve, connect its AUDIO output to driving_audio as well.

3. Video and audio from separate sources

Connect Load Video (Upload) IMAGE to Video Reference, then connect a separate Load Audio node to driving_audio. Use this when the visual reference video and the final audio source are different files.

Both inputs are optional. Connect Video Reference when visual guidance is needed, and connect driving_audio when the supplied audio should be preserved in the final output.

Video Reference frame rate

Use a 24 fps source for Video Reference. Load Video (Upload) may accept files recorded at 25 fps or another frame rate, but acceptance alone does not guarantee correct temporal alignment with H3. For a non-24 fps source, set force_rate to 24 in Load Video (Upload), or convert the file to 24 fps before loading it. If the source is already 24 fps, leave force_rate at its default and do not resample it.

Current validation status

[ v3.3 ]

V3.3 adds Timeline Video conditioning for long-form MiniMax H3 generation. A reference video can now be processed in chunk-local time slices, allowing motion and scene continuity to be carried across multiple 5-second chunks while keeping the reference resolution independent from the output resolution. The Efficient 0.4 MP mode helps reduce memory usage and processing time.

Video assembly has also been improved. Auto seam handling analyzes chunk boundaries and applies guarded corrections for transient flicker, micro-flash, exposure, and color differences. This helps produce more natural transitions between generated chunks without changing the original sampling process.

Existing V3.2.4 workflows remain available as Legacy nodes for compatibility.

[ v3.24 ]

Generate longer native MiniMax H3 video and audio sequences in ComfyUI.

H3 Continuum is a ComfyUI custom node that generates a longer sequence as connected chunks and assembles them into one continuous video.

```text
3 × 5-second chunks → 15-second video
6 × 5-second chunks → 30-second video

The previous video and audio latent context is passed into each continuation chunk. This is not a simple video concatenation workflow.

Main purpose: longer MiniMax H3 generation, not faster generation.

Easy Installation

H3 Continuum can be installed directly from ComfyUI Manager.

Open ComfyUI Manager
Search for H3 Continuum or Continuum
Select Install
Restart ComfyUI
Load one of the included sample workflows

Manual installation and the latest documentation are available on GitHub:

GitHub:
https://github.com/ukr8b3g-cmyk/ComfyUI-H3-Continuum

What It Does

H3 Continuum divides a longer generation into manageable chunks.

MiniMax H3 Model
↓
H3 Continuum Sampler
↓
ComfyUI Core Video / Audio VAE Decode
↓
H3 Continuum Assemble
↓
Final video

Each continuation chunk receives latent context from the preceding chunk. Overlapping context is removed during assembly, and the final frame and audio counts are aligned to the requested duration.

Main Features

Connected long-form MiniMax H3 generation
Native video and audio latent continuation
Fixed, List, and Timeline prompt formats
Automatic prompt-format detection
T2VA, I2VA, FL2VA, Last Frame and Reference workflows
Up to three Reference Images
Reference Audio conditioning
First Frame and Last Frame conditioning
Configurable continuity context
Run Storage and automatic resume
Partial regeneration from a selected chunk
Optional Spectrum interoperability
Standard and Turbo sample workflows
ComfyUI Core VAE Decode compatibility

Included Sample Workflows

Two example workflows are provided.

Standard Workflow

Recommended when output quality and temporal consistency are the priority.

Standard MiniMax H3 sampling
Spectrum can be enabled
Suitable for quality-focused generation
Reference Image and Reference Audio supported
RTX upscaling can be enabled when required

Turbo Workflow

Recommended for faster tests and iteration.

LightX2V MiniMax H3 Turbo LoRA
8-step example configuration
Spectrum is bypassed by default
Faster than the standard workflow in tested configurations
Some loss of facial detail or additional artifacts may occur

Turbo LoRA models:

https://huggingface.co/lightx2v/Minimax-h3-Turbo/tree/main

MiniMax H3 models and documentation:

https://huggingface.co/MiniMaxAI/MiniMax-H3

Models and LoRAs are not included with this custom node.

Reference + Continuation

Reference Images remain available across all generated chunks.

A typical setup is:

Picture 1 → face and identity
Picture 2 → full-body appearance and clothing
Picture 3 → environment or an additional visual reference
Audio 1   → vocal, music or audio-performance reference

Ref2VA is the reference-specialized checkpoint and is generally the first choice for stronger reference fidelity.

FL2VA with Reference conditioning is also allowed. H3 Continuum does not automatically replace or switch the connected model.

Spectrum Integration

Spectrum is optional. H3 Continuum also works without it.

With a compatible Spectrum release, H3 Continuum sends a continuation signal only when generating later chunks.

Chunk 1 → normal Spectrum sampling
Chunk 2+ → Continuum Actual Prefix 2

This allows Spectrum to coordinate its spectral forecasting with the continuation context instead of treating every chunk as an unrelated generation.

Benefits include:

Automatic identification of continuation chunks
Actual Prefix applied only where required
No manual prefix switching between chunks
Reduced risk of duplicated prefix processing
Compatibility with standard ComfyUI workflow execution

Spectrum remains an approximate accelerator. Motion, anatomy, audio and detail can differ from a non-Spectrum result, so quality comparisons should use the same prompt and seed.

Spectrum:

https://github.com/xmarre/ComfyUI-Spectrum-MiniMax-H3

Run Storage and Resume

Enable Save + Auto Resume to preserve completed raw video and audio chunks.

If a generation is interrupted, H3 Continuum can reuse compatible saved chunks and continue from the first missing chunk.

It can also regenerate from a selected chunk while preserving the compatible prefix.

Chunk 1–3 completed
↓
Generation interrupted
↓
Queue the workflow again
↓
Chunks 1–3 reused
↓
Generation continues from Chunk 4

Run Storage verifies the sampling contract, model route, references, resolution and saved chunk files before reuse.

Prompt Formats

Fixed

One prompt is used for every chunk.

List

Separate prompts are divided with:

---

Timeline

[0-5s]
First scene description

[5-10s]
Second scene description

[10-15s]
Third scene description

Prompt Format = Auto detects the appropriate format automatically.

Incomplete timeline coverage produces diagnostics and safe fallback behavior rather than unnecessarily stopping every generation. Structurally unusable input is still reported as an error.

Tested Configuration

The current Windows implementation has been tested with:

GPU                 NVIDIA RTX 5060 Ti 16GB
ComfyUI             MiniMax H3-compatible Core build
Chunk Duration      5 seconds
Typical Length      3 or 6 chunks
Continuity          Balanced 22 frames
Standard Sampling   RES Multistep
Spectrum Interop    Actual Prefix 2

The node is not limited to RTX 50-series GPUs. Actual compatibility, generation speed and usable resolution depend on the MiniMax H3 model, GPU memory, ComfyUI configuration and installed acceleration nodes.

RTX 4060 and other configurations have not been formally validated by this project.

Frequently Asked Questions

Is this only a workflow?

No. H3 Continuum is a ComfyUI custom node package. The included workflows are ready-to-use examples.

Does it generate one native 30-second sample?

No. It generates connected chunks and assembles them into one longer output while carrying video and audio latent context forward.

Does it make MiniMax H3 faster?

Speed is not the primary purpose. H3 Continuum is designed for longer generation. Spectrum and Turbo LoRAs can reduce generation time in some configurations.

Is Spectrum required?

No. It is an optional acceleration and interoperability path.

Can I use the Turbo LoRA?

Yes. A Turbo sample workflow is provided. Spectrum is bypassed by default in that workflow because combining both can change quality or introduce artifacts.

Which model should I use for Reference Images?

Ref2VA is the reference-specialized option. FL2VA with Reference conditioning is also allowed, but reference fidelity may differ.

Are the models included?

No. MiniMax H3 checkpoints, text encoders, VAEs, Turbo LoRAs and optional acceleration nodes must be installed separately.

Can an interrupted generation be resumed?

Yes. Enable Run Storage before generation. Compatible completed chunks can then be reused.

Can I regenerate only the later part?

Yes. Run Storage supports regeneration from a selected chunk while retaining a compatible earlier prefix.

Are chunk boundaries always invisible?

No generative continuation system can guarantee a completely invisible boundary. H3 Continuum preserves latent context and removes duplicated overlap, but difficult motion, lighting changes and large prompt transitions can still produce flicker or visual changes.

Does Reference Audio guarantee exact lip synchronization?

Reference Audio conditions MiniMax H3’s native joint video/audio generation. It can guide vocals, rhythm, expression and mouth movement, but it does not guarantee sample-identical audio reproduction or frame-perfect lip synchronization in every generation.

Does it support audio continuity?

Yes. Video and audio latent context are carried together. The assembler also provides an optional Audio Seam mode for boundary-local audio correction.

Is RTX 5090 required?

No. Development and runtime validation were performed on an RTX 5060 Ti 16GB. Lower-memory configurations may require reduced resolution, offloading or other ComfyUI memory optimizations.

What license is used?

H3 Continuum is released under the MIT License.

Links

Custom Nodes

The included Standard and Turbo workflows use the following custom nodes.

- H3 Continuum

https://github.com/ukr8b3g-cmyk/ComfyUI-H3-Continuum

- rgthree-comfy

https://github.com/rgthree/rgthree-comfy

- ComfyUI-Easy-Use

https://github.com/yolain/ComfyUI-Easy-Use

- ComfyUI-KJNodes

https://github.com/kijai/ComfyUI-KJNodes

- ComfyUI-Spectrum-MiniMax-H3

https://github.com/xmarre/ComfyUI-Spectrum-MiniMax-H3

- NVIDIA RTX Nodes for ComfyUI

https://github.com/Comfy-Org/Nvidia_RTX_Nodes_ComfyUI

Spectrum and RTX upscaling are optional generation paths, but installing all listed custom nodes allows the included workflows to load without missing-node warnings.

Models

- MiniMax H3

https://huggingface.co/MiniMaxAI/MiniMax-H3

- LightX2V MiniMax H3 Turbo LoRA

https://huggingface.co/lightx2v/Minimax-h3-Turbo/tree/main

Models and LoRAs are not included in the workflow ZIP.

Main Links

- GitHub and documentation

https://github.com/ukr8b3g-cmyk/ComfyUI-H3-Continuum

- Install from ComfyUI Manager

Search for H3 Continuum

Files with SHA256: 5682ff046b95ae41db4d993efe0e1d46a37cbdfbefb9d2b8bb82bb6a7c995512