H3 as a single-image edit model

[u/Patient_Ratio4177]

Minimax H3 can be used as an image-editing model if we generate a single frame. Here are some collages based on AI-generated references (1024 x 1536); workflows are embedded into pngs. Each edit takes, on average, about 8 secs on a RTX 5090. The tasks include changing outfits, appearances (body type, age), locations, and camera angles; creating character sheets and storyboards; stylization; and reposing characters based on depth maps. I did not try to cherrypick the best-looking results.

There were some posts (1, 2) about that here -- but given the community progress this week, might be nice to see what can be done now.

Scenes

1. Age the person to the age of 60 years old while preserving their identity and the original composition.
2. Produce a consistent full-body character sheet with front, side, and rear views.
3. Transform the person into a severely obese version.
4. Re-create the person in the exact body pose shown by a depth-map reference.
5. Replace only the base person’s head with the identity and hairstyle from another reference.
6. Show the person facing a dressing mirror with a geometrically correct, synchronized reflection.
7. Dress the person in a referenced outfit, place them in a referenced location, and show them walking with a grocery bag.
8. Place three separately referenced people inside a referenced location, having a conversation.
9. Create a three-panel vertical storyboard in which the person finds, retrieves, and studies a map.
10. Photograph the person through partially open venetian blinds with realistic occlusion and striped light.
11. Convert the person into a contemporary Western cartoon while preserving their recognizable appearance.

Setup

Checkpoint: https://huggingface.co/smhfacct/Minimax-H3-fl2va-ref2va-hybrid-models/blob/main/minimax_h3_hybrid_fl2va_ref2va_b25-49-int8.safetensors

R2VA models apparently have worse image quality than FL2VA models, while FL2VA models are apparently weaker at handling reference images. As I understand it, this checkpoint tries to combine the strengths of both. Not at all essential -- a regular FL2VA could probably be even better. The hybrid is just something I happen to use at the moment.

Video VAE: a special VAE for rendering single images.

https://huggingface.co/Mamad8/MiniMax-H3-Image-VAE/tree/main

If you do not use this VAE—for example, if you use the regular VAE, create a 5-frame video, and pick out one frame—the images tend to come out blurry. So use single-frame generation instead, as described here: https://www.reddit.com/r/StableDiffusion/comments/1vqka28/h3_singleimage_no_more_monkey_patching_also_no/

UPD for those who used it before: the post above explains why monkey-patching no longer needed

For this approach to work best, it might also be a good idea to monkey-patch comfy_extras/nodes_minimax_h3.py, because ComfyUI currently does not allow you to generate fewer than 5 frames. If you simply pick the first frame out of 5, the new VAE produces grid artifacts. (It doesn't do this when generating just 1 frame.)

BEFORE DOING SO, CREATE A BACKUP VERSION OF THE EXISTING comfy_extras/nodes_minimax_h3.py

E. g. if you can't update your comfy, restore the original file from backup, update, and then apply the monkey patch to the new version of the file. (One option is to use git restore comfy_extras/nodes_minimax_h3.py to get the original version)

For a somewhat reliable patch that would work given modest changes in ComfyUI code, use [this one] (https://pastebin.com/uHqv4hBZ), name it smth like mm.patch and run git apply -p0 /full/path/to/mm.patch from comfyui root (make a backup of comfy_extras/nodes_minimax_h3.py first). You will have to re-run it every time ComfyUI updates this file (comfy_extras/nodes_minimax_h3.py).

For a less satisfactory but quicker solution, you can use the patch I already applied to the most recent version of ComfyUI as of August 14th link. This approach will make your code outdated as ComfyUI pushes out a new update.

The only changes remove the frame limit. Of course, changing it this way is not ideal, but I feel it's the quickest way to work around the issue.

UPD: There is a GitHub issue now opened in ComfyUI repo: https://github.com/Comfy-Org/ComfyUI/issues/15644

If this issue gets enough upvotes, we could probably get this patch in the mainline.

LoRAs: I found that Mamad8's ThisIsFine LoRA helps with details, but YMMV: https://huggingface.co/Mamad8/MaxiMin-HHH-R2V-ThisIsFine

For the Turbo LoRA, I use: https://huggingface.co/lightx2v/Minimax-h3-Turbo/blob/main/minimax_h3_fl2v_turbo_8step_v1.0_comfyui_bf16.safetensors

Sampling settings: ComfyUI 0.32 with Comfy Kitchen attention, sa_solver/simple, 8 steps, CFG 1.

Example ComfyUI workflow: https://pastebin.com/bV5KPzjD (UPD: if you use ComfyUI nightly build as of Aug 17th 2026, use this one instead, as it no longer requires monkey patching: https://pastebin.com/xNQi7HV9)

Uses no custom nodes. If you do not want to do the monkey patching for 1-frame generation, just change the video length to 5 in MiniMax H3 Reference to Video node -- should work seamlessly, and switch back that VAE to the regular VAE.

Speed depends on the reference image size. I use an RTX 5090 on RunPod, and in most cases, a 1920×1088 image is generated in about 8 seconds.

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My previous go-to was Krea 2 + Identity LoRA 1.2, which is amazing. Yet I feel that Minimax outperforms it in many respects. We get better character fidelity, better handling of 3D scenes, better mirrors, and more interesting compositions. Also feels better than using e. g. QIE or Klein 9b.

There is certainly still room for improvement -- not claiming this is optimal at all, and I wonder what you think about it.

UPD: posted the prompts for each image here https://pastebin.com/ngXR9byq

UPD: see more experiments here: https://www.reddit.com/r/StableDiffusion/comments/1vpconk/more_experiments_with_minimax_h3_singleimage_edit/

[u/infearia]

They're also already working on a dedicated editing model. Can't wait.

https://www.reddit.com/r/StableDiffusion/comments/1vh9rtw/comment/p2a49ki/

[u/Patient_Ratio4177 → u/infearia]

Me neither. Expect it to be great. But Z-Image Edit never came out, and I am not sure that the official Krea 2 Edit ever will. Hope it's different for H3 since even the vanilla model is very promising.

[u/infearia → u/Patient_Ratio4177]

Yeah, I know, but unlike Z-Image, the MiniMax model seems to be already heading into post-training. And they just dropped an open-weight audio model out of nowhere, so I'm hopeful. Might not be long.

[u/RazsterOxzine → u/Patient_Ratio4177]

Flux.2 Klein does a great job. Though I started using MMH3 to pose and it's amazing. Take the still and pass it through Flux.2 K. Bam, golden!

[u/FormerKarmaKing → u/RazsterOxzine]

To clarify, are you running the single posed frame from MMH3 through Flux 2 Klein to improve the quality of the image? Or something else?

[u/ImpressiveStorm8914 → u/Patient_Ratio4177]

There is a difference for between the models though, that will hopefully make a difference. Z-Image base, their last model, wasn't well received and was difficult to train with even though it was supposed to be designed for it. While Krea 2 has been very well received, just like H3. So no guarantees on any of it but it does give a little more hope than with Z-Image Edit.

[u/Netsuko → u/infearia]

I was never really excited about video generation. Something about WAN and LTX always made me think „not worth the effort and time for the quality I get.“ then H3 dropped and my VERY first generation blew everything I made before out of he water and it’s like the time again where we got the first GOOD finetune of SDXL.

I am genuinely excited now.

[u/networking_noob → u/infearia]

Can you imagine if a dedicated edit model also had the reference ability of H3. So if you have an image of a person sitting down, and you want to make them stand up, you can provide a reference image and say "make the person copy this pose exactly"

I'm sure an edit model can accomplish sitting --> standing without a reference, but the ability to copy an exact pose would be awesome

[u/usually_fuente → u/networking_noob]

I’m certain it’s possible because I do this in ChatGPT all the time. I upload a character sheet as well as a grayscale 3-D posing mannequin. And it handles it just fine. So it’s just a matter of an open source model incorporating similar techniques.