Rotoscoping for Pixel Art Game Sprites
Summary of how Mimigame recreates Jordan Mechner’s Prince of Persia (1989) rotoscoping technique with modern tools to animate a Great Pyrenees dog.
Key Takeaway
Rotoscoping — tracing real video footage frame by frame — produces fluid, lifelike motion that hand-drawn keyframe animation can’t match. Mechner filmed his brother; this project filmed a dog running in snow. The technique translates directly from 1989 to 2026 with modern tools (PIL/Pillow instead of hand tracing, LibreSprite instead of Deluxe Paint).
The Pipeline
- Record real video (171 frames of Mimi running)
- Select key poses (~every 10th frame, 9 total for complete gallop)
- Process to 80x80px reference images
- Create pixel art sprites following PoP style rules
- Assemble into seamless loop sprite sheet
9-Frame Dog Gallop Cycle
Contact → Recoil → Passing → Lift → Airborne → Extended → Landing → Contact Rear → Push. Each frame must flow seamlessly back to frame 1.
Prince of Persia Style Rules
- Bold outlines (2-4px), limited palette (11 colors max), geometric not photorealistic, clear silhouettes at any size
- 80x80px frames at 10-12 FPS (separate from 60 FPS render loop)
- NEVER use image smoothing — always nearest-neighbor scaling
- Sprite sheet: ~3KB total, <1KB per frame
Critical Gotcha
LibreSprite 1.2-dev V8 scripting is broken (embedder-vs-build mismatch) — GUI works perfectly but scripting does not. Use PIL/Pillow for automation instead.
See also: rotoscoping, source-claude-usage-patterns