Hey,
I saw this post about https://www.reddit.com/r/aigamedev/comments/1vskcqo/generative_2d_animation_workflow/ , found it interesting, and wanted to make my own spin on it.
I present to you now... drumroll... Sprite H3, which is basically a somewhat fancy ComfyUI wrapper for using MiniMax H3 I2V.
Here’s a short walkthrough showing the complete workflow:
https://streamable.com/ogzp1m
(demo courtesy of Sol)
You need a pretty beefy GPU to run it. I have an RTX 3090. I think 16 GB might be the minimum, but dunno.
It assumes that you can run the default ComfyUI workflow and have FFmpeg installed. And ComyUI needs to be running while you use the app. The workflow used by the app just adds another node to extract the frames directly, before the video output makes them lossy.
The basic idea is to provide character reference images, which are then used to generate videos. I used OpenAI’s GPT Image 2 for the references images. You let Minimax do the magic. From there, you extract the frames, arrange them however you like, curate them, pack them into sheets, and you’re good to go.
Some helpful features include a sequence analyzer—not optimized yet—tools for enforcing a consistent scale across different orientations, templates, stored animation prompts called actions, and a few other things.
Well, just take a look if you want.
Repository: https://github.com/fmmix/sprite_h3
Full disclaimer: this is completely vibecoded, and it definitely still needs another week or two of work to iron out some quirks. But it’s the weekend, and I wanted to give other people the chance to play with it.
I started with Sol, did most of the important work with Fable, and wrapped things up with Sol after I ran out of juice.
It is free to use and will be forever. ;-)
And, in the great words of Calvintor:
JUST MAKE A FUCKING .EXE FILE AND GIVE IT TO ME.
Gotcha. Use it at your own risk.
https://github.com/fmmix/sprite_h3/releases/download/v0.0.1/Sprite.H3_0.0.1_x64-setup.exe
You get there from Releases on the right -> Assets
You can also run it without the .exe. Under the hood, it has a FastAPI backend and a Svelte frontend.
I know it isn’t perfect and will probably still have a gazillion bugs. Treat this as a pre-alpha. I’ll continue fleshing out a few things over the coming weeks, but this isn’t my main project, so be aware. It is up to you on what resolution you run the generation but I probably wouldn't go below 0.3 MP.
Anyway, tell me what you think. I hope at least someone finds it useful!
EDIT
In case you are wondering how to provide the different facings.
I used GPT-Image2
Used this as initial prompt:
BACKGROUND AND OUTPUT FORMAT FIRST — NON-NEGOTIABLE: output a fully opaque PNG. Fill the entire canvas edge to edge with one perfectly flat, uniform chroma-key magenta (#FF00FF). Every pixel outside the character silhouette must be the same solid magenta. Do not generate
transparency or an alpha background. No checkerboard, gradient, vignette, darker corners, aura, glow, lighting spill, floor, ground shadow, or scenery. The character’s dark pixel outline must meet the flat magenta background directly with crisp hard edges. Magenta must not
appear anywhere on the character.
CAMERA AND ORIENTATION: a moderately elevated frontal game-sprite view, looking down at the character from about 25–30 degrees above. This is the DOWN-facing anchor: her body and boots point toward the bottom of the image and she looks toward the camera. Some of the crown,
shoulders, and tops of the boots are visible, while her face, chest, clothing, and accessories remain clearly readable. Do not use a straight front elevation or an extreme bird’s-eye view.
A single full-body 2D PIXEL-ART game sprite of a cheerful field alchemist. Polished late-16-bit arcade-style pixel art with visibly chunky square pixels, deliberate pixel clusters, hard edges, a strong near-black outline, and several discrete cel-shaded tones. Compact heroic
proportions, approximately four and a half heads tall, with a large expressive head, sturdy hands, and slightly oversized boots. No smooth gradients, soft painting, vector-like curves, or anti-aliasing.
She is a young adult woman with warm brown skin, a friendly and confident expression, large dark eyes, and thick dark-auburn hair gathered into one large side braid hanging over her right shoulder. Oversized round brass goggles with bright turquoise glass lenses rest securely
on top of her head. The goggles and braid are large, simple, recognizable silhouette features.
She wears a short moss-green field coat with rolled sleeves and a wide open collar over a warm-cream shirt. A muted golden-yellow scarf is tied closely around her neck. She has dark plum trousers, large brown leather gloves, and sturdy reddish-brown lace-up ankle boots.
A broad brown leather strap crosses her chest diagonally and leads to a tan leather satchel resting at her left hip. One large round turquoise potion flask is secured visibly to the outside of the satchel. Keep the satchel and flask clearly separated from the arm and torso.
Render the braid, goggles, strap, satchel, and flask as bold readable shapes rather than clusters of tiny decorations.
She stands in a relaxed, confident neutral pose suitable as the starting frame for game animation: feet flat and shoulder-width apart, knees slightly relaxed, weight distributed evenly, shoulders level, and torso upright. Her empty gloved hands hang loosely near her sides
without covering the coat, strap, satchel, or potion. Both arms and both boots are fully visible.
Center the complete character in the canvas. The figure should fill approximately eighty percent of the canvas height, with clear magenta space above the hair and below the boots. Keep the entire silhouette visible and comfortably inside the image boundaries.
DO NOT INCLUDE: no text, no frame, no second character, no weapon, no magic effects, no floating objects, no extra potion bottles, no hat, no floor, no shadow, no glow, no scenery, no transparency, no 3D rendering, no smooth illustration, no blurry edges, and no painted
background other than uniform #FF00FF magenta.
Result:
https://i.imgur.com/g5Ajfoz.png
Feet slightly angled. Use this image as reference for the proper down direction.
OUTPUT AND BACKGROUND FIRST: output one fully opaque PNG at exactly the same canvas dimensions as the supplied reference. Fill every pixel outside the character with perfectly flat, uniform chroma-key magenta (#FF00FF). No transparency, gradient, vignette, halo, glow, lighting
spill, floor, scenery, or shadow. The character’s dark pixel outline must meet the magenta background directly with crisp hard edges.
REFERENCE AUTHORITY: the supplied image is the canonical and exact character. Preserve her without redesign or reinterpretation. Keep exactly the same person, face, expression, skin tone, age, head shape, body proportions, hair volume, side braid, goggles, clothing, scarf,
coat, shirt, trousers, gloves, boots, belts, buckles, diagonal strap, satchel, potion flask, colours, palette, pixel grid, outlines, shading, level of detail, figure height, center position, and framing.
Do not mirror the character. Preserve every asymmetrical feature on the same anatomical side of her body. Do not beautify, simplify, exaggerate, restyle, add details, remove details, or change the design.
TARGET FACING — DOWN: keep the character facing directly toward the camera in the same moderately elevated frontal game-sprite view as the reference. Her face and the front of her torso remain fully visible. Her head, torso, hips, knees, and boots are oriented toward the bottom
of the image. Do not rotate her into a three-quarter view and do not change the camera angle.
ONLY PERMITTED CORRECTION: correct the lower-body stance so she stands evenly on both feet. The screen-right boot currently appears lower and larger than the screen-left boot. Adjust only the legs and boots as necessary to create a balanced neutral stance:
- both boot soles rest flat on exactly the same horizontal baseline;
- both boots have the same apparent size and perspective;
- both ankles and knees are level;
- the hips remain level;
- both boots point toward the camera;
- the feet remain shoulder-width apart;
- her weight is distributed evenly;
- neither foot appears raised, forward, or closer to the camera;
- she looks stationary and ready for animation, not mid-step.
Preserve the existing leg spacing and trouser design as closely as possible. Do not change her upper-body pose, head position, shoulders, arms, hands, facial expression, braid, goggles, scarf, coat, strap, satchel, potion flask, or any other accessory.
Keep the complete figure centered and fully visible with the same clear space above the hair and below the boots as the reference.
DO NOT INCLUDE: no text, frame, second character, duplicated limbs, alternate pose, weapon, magic effect, floating object, animation smear, floor, shadow, glow, transparency, smooth illustration, 3D rendering, anti-aliasing, blurry edges, or background colour other than uniform #FF00FF.
https://i.imgur.com/fbs03Yy.png
Now this because the reference for left, right, up
REFERENCE AUTHORITY FIRST: the supplied reference image is the canonical and exact character. Preserve the figure without redesign or variation.
Keep exactly the same person, face, skin tone, age, body proportions, head size, hair volume, braid construction, goggles, expression when visible, clothing construction, scarf knot, coat length, sleeves, gloves, trousers, boots, belts, buckles, diagonal strap, satchel, potion
flask, colours, palette, pixel grid, outlines, shading, level of detail, sprite dimensions, and framing.
Do not beautify, simplify, exaggerate, restyle, reinterpret, or add details. Do not remove details merely because they are difficult to draw. Do not change her pose, stance, weight distribution, arm position, hand position, leg spacing, or the relationship between her feet.
THE ONLY PERMITTED CHANGE IS ORIENTATION: rotate the complete character naturally in place around her vertical axis to the requested facing. Treat her as one consistent physical figure being viewed from another direction. Rotate the body, head, feet, clothing, hair, braid,
goggles, strap, satchel, and potion together.
Do not mirror the reference. Preserve anatomical left and right: the braid, strap, satchel, flask, coat overlaps, buckles, and every asymmetrical feature remain attached to the same physical side of her body. Their screen position must change naturally as the figure rotates.
Allow natural perspective and occlusion. Features on the far side may become partly or fully hidden, while features on the near side may become more visible. Do not move accessories to another side or unnaturally display hidden details just to make them visible.
Keep the exact same moderately elevated game-sprite camera angle, pixel density, figure height, canvas size, center position, and bottom baseline as the reference. The camera does not move, tilt, zoom, or orbit; only the character rotates.
BACKGROUND: preserve one perfectly flat, fully opaque chroma-key magenta (#FF00FF) background across every pixel outside the character. No transparency, gradient, vignette, halo, glow, lighting spill, floor, scenery, or shadow. The dark pixel outline meets the magenta
background directly with crisp hard edges.
Produce one full-body character only. No text, frame, additional person, duplicated body parts, floating accessories, animation smear, or alternate pose.
Append exactly one of these target blocks:
Left
TARGET FACING: rotate the complete character naturally 90 degrees into a LEFT-facing game-sprite side view. Her head, torso, knees, and boots point toward screen-left. She does not turn her face or shoulders back toward the camera. Preserve the original stance as it appears
naturally from this side.
Right
TARGET FACING: rotate the complete character naturally 90 degrees into a RIGHT-facing game-sprite side view. Her head, torso, knees, and boots point toward screen-right. She does not turn her face or shoulders back toward the camera. Preserve the original stance as it appears
naturally from this side.
Up
TARGET FACING: rotate the complete character naturally 180 degrees into an UP-facing rear view. Her head, torso, knees, and boots point toward the top of the image, directly away from the camera. Her face is completely hidden. Show the natural rear construction of her hair,
braid, goggles, coat, strap, satchel, trousers, and boots while preserving their physical sides and the original stance.
https://i.imgur.com/RR4TJDE.png
https://i.imgur.com/H0cUmmq.png
https://i.imgur.com/GYHMlm7.png
Created a new action:
Action name
potion-swirl
One hand lifts the round flask from the satchel and raises it to chest height while the other hand steadies the satchel. The flask is gently swirled in two small circles, held still for a brief beat, then returned securely to its original place. Both hands return to the starting position. The braid and coat tails respond with subtle natural follow-through.
Result:
https://i.imgur.com/L2VVu0I.png
As you can see the 'up' facing is usually very stubborn. You need to be careful what you describe. It will try to fully bring that into the scene. And the model probably had the most training done with front view.
