A HUD interaction that lasts four seconds can take a day to communicate. The designer builds a static comp, writes a paragraph about how the health bar should recoil on a hit, records a screen capture of some other game as a rough reference, and hands the bundle to an engineer who reads all of it slightly differently. Two builds later, the easing is wrong, the shake is too aggressive, and nobody can point at what "right" would have looked like.

Motion is the part of interface design that survives translation worst. Which is why the teams experimenting with generative video for UI work aren't chasing cinematics — they're trying to skip the argument and show the thing.

Why this didn't work before

Until recently, generative video was actively bad at interfaces. Screens were the worst-case input: a HUD would melt across frames, buttons would multiply, labels would degrade into letter-shaped noise the moment the camera moved. You could get a beautiful shot of a forest and not a single usable frame of a menu.

Minimax H3 is unusually stable here, and stability is the whole ballgame for UI. Panels keep their geometry through a transition. Icon shapes stay the same shape. Text stays readable at 1440p instead of dissolving into approximate glyphs. That reliability is what turns a video model from a mood-board generator into something you can prototype against.

The loop that actually works

The workflow that's stuck isn't prompt-writing so much as reference assembly. H3 takes text, images, video, and audio into a single shared context and reasons across them together, so you can feed it your real interface rather than describing one.
A typical pass looks like this. Export the current screens as stills — the actual layout, the actual icon set, the actual type. Attach a short reference clip if there's an existing motion language you want the prototype to inherit, whether that's a competitor's menu feel or a previous build of your own. Then describe the interaction in prose: the press, the delay, the overshoot, the settle, what the camera does while it happens.
What comes back is a 5-to-15-second clip at 24 FPS showing your interface, in motion, with a specific opinion about timing. It is not engine-accurate. It is enormously more specific than a paragraph.

The revision behaviour is what makes it a loop rather than a lottery. H3 edits locally: change the panel colour, remove an element, swap an icon, adjust one part of the animation, and the rest of the frame holds still. You're narrowing a single variable per pass instead of re-rolling the entire shot and hoping the good parts come back.

Sound is half of interface feedback

This is the part teams underestimate. UI feel is not purely visual — a confirm without a chime reads as a failed input, and a menu whoosh that lands two frames late makes the whole transition feel broken. Yet motion specs are almost always delivered silent, with audio bolted on months later by someone who never saw the prototype.

H3 outputs native stereo audio generated alongside the picture, in the same pass. Clicks, whooshes, impact thumps, ambient layers under a pause menu — they arrive synced because they weren't matched to the footage afterwards. For a prototype that's a genuine change in what you can evaluate. You stop reviewing an animation and start reviewing an interaction.

It also means the sound designer gets a target instead of a brief. Even if none of the generated audio ships, it establishes intent in a way a spreadsheet of event names does not.

Where it stops

Worth being blunt about the limits, because overselling this wastes people's time.
Fifteen seconds is a ceiling, so you're prototyping a moment, not a flow. There's no export to Unity or Unreal — nothing here produces curves, state machines, or anything an engineer can drop into a build. Frame-exact timing still has to be authored properly downstream; what you're generating is a target, not an implementation. And the model is inferring plausible interface behaviour, which means it will occasionally produce motion that looks good and violates your input model.

The honest framing is that this replaces the pitch stage, not the production stage. It's the thing you show in a review to end a debate, not the thing you ship.

Teams trying MinimaxH3 AI Video for this usually run the same test first: feed it a screenshot of their own game's menu and ask for a transition. Whether the panels hold their shape tells you within one render whether the approach is viable for your art style.

Iteration is the whole point

UI motion is not a one-shot discipline. It's twelve versions of the same button press with slightly different easing, viewed back to back, until the team agrees which one feels correct. That's the only way anyone has ever arrived at good interface feel, and it's the reason per-clip cost matters more here than in most use cases.

H3's per-second cost sits well below comparable video models, which is what makes running a dozen variants of a two-second interaction a reasonable Tuesday rather than a budget conversation. Current rates are on the Minimax h3 pricing page, and it's worth doing the arithmetic against what a day of a motion designer's time costs before deciding this is a toy.

The model also ranks first on the Artificial Analysis video editing leaderboard, ahead of Seedance 2.0 — editing rather than generation, which maps neatly onto what prototyping actually is. Nobody's first render is right. The question is how cheaply you can get to the fourth.

The realistic version of this

Generative video isn't going to design your interface. It has no model of your input latency, your accessibility requirements, or why that panel is where it is.

What it does is compress the distance between an idea about motion and something a team can react to — from a day to about ten minutes, with sound attached. For a discipline where most of the cost is disagreement about things nobody has seen yet, that turns out to be worth a lot.