What’s the difference between key art swap and character swap modes?

Key art swap emphasizes scene-level changes (background, lighting, color palette) using your key art as guidance while preserving the subject. Character swap targets the subject’s identity and attire to match a character reference. The mode toggle is handled via SetNode/GetNode, which routes the reference conditioning into MiniMaxH3ReferenceToVideo differently.

How do I get stable results across frames?

Keep your source clip well-lit and steady, use a high-quality guide image, and tune the MODIFY parameters. Lowering denoise/style strength preserves more original structure; increasing temporal/consistency weights (fed by PrimitiveFloat/ComfyMathExpression into MiniMaxH3ReferenceToVideo and the sampler) reduces flicker. Preview a short segment and adjust before rendering the full clip.

Which models do I need to load?

Load the open-weights MiniMax H3 in UNETLoader, a compatible text encoder in CLIPLoader, and a matching VAE in VAELoader. The sampler path uses KSamplerSelect, BasicScheduler, SamplerCustomAdvanced, and BasicGuider to drive diffusion steps for MiniMaxH3ReferenceToVideo.

Do I have to replace the audio?

No. In VOICE OPTIONS you can keep the original audio or use the replacement path if configured. VAEDecodeAudio handles the final audio decoding. If you choose replacement, set the language/voice options provided in that group; otherwise, pass through the source audio.

Minimax H3 Video Restyling - ComfyUI Workflow

This workflow restyles an existing video using the open-weights MiniMax H3 model, guided by a reference “key art” image or a character image. In key art mode, it transfers background, palette, and lighting while preserving the performance; in character swap mode, it targets the subject’s appearance for a full identity change. The core is the MiniMaxH3ReferenceToVideo node, driven by UNETLoader (MiniMax H3), CLIPLoader (text conditioning), RandomNoise, and a sampler chain built from KSamplerSelect, BasicScheduler, SamplerCustomAdvanced, and BasicGuider. VAELoader and VAEDecode convert generated latents back to frames, and ImageFromBatch lets you QC results mid-run.

ResolutionSelector and VHS_VideoInfo handle the practicalities—frame size, fps, and clip duration (the clip length parameter expects whole seconds). SetNode/GetNode are used as convenient toggles and parameter routers, including the mode switch between key art swap and character swap. LoadImage supplies your guiding key art or character reference, while OpenRouterLLMNode (in the GENERATE PROMPT group) can help draft a shot-specific prompt that CLIPLoader uses for text conditioning. A VOICE OPTIONS branch can keep your original audio or pass it to a voice-replacement path; VAEDecodeAudio decodes the final audio stream for muxing with the new visuals.

The result is a VFX-friendly process for look development and restyling: keep the motion and timing of your source while re-lighting the scene, shifting color mood, replacing backgrounds, or swapping a character—useful for previz, mood boards, and quick creative iterations.

API

Use this workflow from code

Every Comfy workflow is a JSON graph. The payload below is this workflow, exactly as ComfyUI runs it — fetch it from the URL, keep it in version control, or load it in ComfyUI and run it node by node.

58a3f7167dba.json

Fetching workflow JSON…

Run it from TypeScript or Python with the Comfy SDK. The same code targets Comfy Cloud or a ComfyUI you host yourself — only the base URL changes.

// Install (beta)
npm i @comfyorg/sdk

// Run this workflow (TypeScript)
import { Comfy } from "@comfyorg/sdk";

const client = new Comfy({ apiKey: "comfyui-..." });
const wf = await client.workflows.fromFile("workflow_api.json");
const job = await client.run(wf);
await job.getOutputs("<output-node-id>")[0].toFile("output.png");

The SDK takes a workflow in API format: open this workflow in ComfyUI and use File → Export Workflow (API).

Comfy Cloud API access requires a plan with an API key.

SDK docs Get an API key

FAQ

Frequently Asked Questions