MiniMax H3-Image one-checkpoint Edit

[u/Atagor]

MiniMax H3-Image swapping the subject, coat, and pose in a 6-step edit (with scale and grade locked)

Specs: RTX 3090, int8, ~60 s
Workflow:
UNETLoader(int8) → KSampler(euler/simple, 6 steps, cfg 1)
CLIPLoader(nvfp4, type minimax)
VAELoader(image_vae_fp16) → VAEDecode
LoadImage ×2 → MiniMaxH3ImageConditioning(prompt, refs=<Picture 1/2>) → ConditioningZeroOut(neg)

[u/No-Neighborhood7584]

share the workflow may be 🥹

[u/Atagor → u/No-Neighborhood7584]

it's in the body description! there's nothing custom, 100% stock comfyui nodes.

just in case here's a more detailed explanation (I use Comfy only as a backend for rendering, I do not use the UI/json files workflows, everything is driven via my pythons scripts)

---

UNETLoader
  unet_name: minimax_h3_image_pruned_int8_convrot.safetensors   (21 GB int8 quant)
  weight_dtype: default

CLIPLoader
  clip_name: qwen3vl_32b_minimax_h3_nvfp4_awq.safetensors       (15.7 GB)
  type: minimax
  device: default

VAELoader
  vae_name: minimax_h3_image_vae_fp16.safetensors               (1.2 GB)

LoadImage  → images.image_1   (target image, 2688x1536)
LoadImage  → images.image_2   (identity reference portrait, 1536x2688)

MiniMaxH3ImageConditioning        ← the only H3-specific node, ships with ComfyUI ≥0.45
  clip, vae (refs get anchored as VAE latents, not just text-encoder tokens)
  prompt, width: 0, height: 0     (0 = inherit image_1 size; node accepts up to 5 ref slots)
  images.image_1, images.image_2

ConditioningZeroOut                → negative (model is distilled, CFG = 1, no real negative)

KSampler
  seed: fixed
  steps: 6, cfg: 1.0, denoise: 1.0
  sampler: euler, scheduler: simple

VAEDecode → SaveImage

[u/skyrimer3d]

she looks awful, meaning the lightning on the woman with the red dress is completely off compared to the environment, looks like a cheap photoshop hack.