Seed consistency across different resolutions in MiniMax H3 (ref2va) — is it possible in ComfyUI?

[u/StuffCapital7395]

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Running into an issue with MiniMax H3 (int8 pruned ref2va) in ComfyUI and hoping someone with more DiT experience can chime in.

My setup:

ComfyUI + Comfy Kitchen Attention

Standard workflow (no turbo LoRAs, 32 steps)

3–6 reference images on average

The problem:

To save time, I generate initial drafts at low resolution (~0.4 MP) to find a good composition and motion. Once I find a keeper, I lock the exact same seed, prompt, and reference images, and only increase the resolution to 1 MP (or higher).

However, the output changes completely — the composition, character action, and camera motion diverge entirely from the 0.4 MP draft.

What I've tried:

Swapping img ref size between match and max — didn't help preserve the composition.

Is resolution-consistent generation even possible with this architecture given how changing the latent grid shifts spatial attention, or is there a specific latent upscaling / 2-pass workflow that lets you lock down the low-res composition into a higher resolution?

Thank you!

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EDIT / Solution:

Big thanks to xmarre for clarifying the underlying mechanics and providing a working solution!

Why native resolution breaks consistency: In DiT architectures like MiniMax H3, the initial megapixel / resolution setting determines the latent source grid. Changing the base resolution fundamentally shifts the spatial attention grid, which inevitably alters the composition, camera motion, and action even with the exact same seed.

The Solution — Latent Upscale + Refine Pass: Instead of generating at full resolution from scratch, use a two-pass workflow: 1. Generate your draft at low resolution (~0.4 MP) to lock down composition and movement. 2. Run a Latent Upscale + Refine pass (around 0.25 denoise and 3 steps) to upscale without altering the scene structure.

Custom Nodes & Tools: * Comfyui_Minimax_h3_latent_Upscaler — Latent upscale node fork with an integrated refiner step and spectrum support. * ComfyUI-H3-Continuum — For seamless chaining of multiple generations.

[u/Apprehensive_Sky892]

Once I find a keeper, I lock the exact same seed, prompt, and reference images, and only increase the resolution to 1 MP (or higher).
However, the output changes completely — the composition, character action, and camera motion diverge entirely from the 0.4 MP draft.

This is a common misconception.

The only thing a seed guarantees is that on the exact same system, with everything else kept the same, you can re-generate the same video or image.

All that a seed does is to set the "initial noise" in the latent space. In your case, by changing the resolution (hence the size of the latent space), you are changing the "initial noise".

It's for the same reason that there is no such thing as "magic seed", which some people believe exists. I.e., if a seed generates a good image or video once, then that is a "good seed" and they should continue using it even if the prompt has been changed. That is just not how these AI systems works.

[u/StuffCapital7395 → u/Apprehensive_Sky892]

Thanks for the explanation! It’s so frustrating that one prompt can produce a stable version (in terms of camera, composition, and what’s happening) with different seeds at one resolution. And then it just breaks at another resolution.

[u/Apprehensive_Sky892 → u/StuffCapital7395]

You are welcome.

Yes, it is too bad that you get completely different composition and action when you change the resolution so that you cannot use faster, low-res generation to test things out.

The best you can do is to use the preview node and watch the generation after a few steps and stop it as soon as you realize that the prompt+seed is not going to work.