MiniMax H3 PreStage

Every image-to-video workflow has a missing step: where does the image come from? MiniMax H3 PreStage is that step for the Creator Palette. It generates a still locally - a start frame, an end frame, a reference, a style sheet - so your video never has to begin from "I guess I'll hunt for a PNG." It's the second node in the pack you'll actually place by hand, and it's spawned from a pill on the Creator or Timeline body, though underneath it's an ordinary, copyable, saveable node.

What makes it interesting is the roster. PreStage can render with Krea 2, Ideogram 4.0, or MiniMax H3 itself. The first two are open weights native to ComfyUI core, so you're not adding a second model family to your life. The H3 branch is the clever one: H3 is a video model, so a "still" from it is actually a short video generation whose first latent frame gets decoded as a picture through the experimental T=1 image VAE. You get a keyframe made by the same weights that will render the shot it opens - no visual whiplash between your reference and your video.

How it works

Like the big Creator node, PreStage has zero sockets. A JSON blob (prestage_data) carries the whole job - arch, prompt, aspect, LoRAs, turbo settings, handoff state - and the node expands into a subgraph that loads, samples, decodes and saves. The handoff to the video pipeline is by file, not by graph edge: results land through ComfyUI's normal image-output path, and the Creator picks up whatever you choose. Because there's no execution edge, queueing both nodes at once is never an ordering race - and an untouched PreStage is a cache hit on the render, so it doesn't cost you wall-clock time.

The inputs that matter

• text - the prompt, backed by the same Prompt Palette editor as the Creator.
• seed, steps, cfg - defaults 0 / 52 / 3.5. Higher-step defaults than video, because this is a still.
• sampler_name / scheduler - euler / simple by default. One wrinkle worth knowing: Krea 2 samples on whatever schedule you pick, but Ideogram 4 owns its own resolution-shifted schedule and ignores scheduler entirely. Don't fight it.

The prestage_data blob also holds the handoff mode - review-then-video, image only, auto image→video, or bypass PreStage - and where the result goes (first frame, last frame, or reference slot). That handoff is deliberately explicit: the pack refuses to silently pick an image for you.

It has no outputs. Stills save under output/minimax/stills/prestage/ and show up in the PreStage Image Lab for review and curation before you commit.

Install and gotchas

Same pack, same install: ComfyUI Manager → search "H3 Creator Palette", or git clone https://github.com/z3rofeels/ComfyUI-H3-Creator-Palette into custom_nodes/, then restart and hard-refresh (Ctrl+F5). Needs ComfyUI 0.34.0+, no extra Python deps, and - depending on which arch you pick - your own Krea 2 / Ideogram 4 / H3 model files in ComfyUI's model folders. The most common confusion is expecting PreStage to need an API key because Krea and Ideogram are names you know from the cloud; they're not - this is all local weights, no signup, no credits.