Emotive Engine
Animation engine with musical time (not milliseconds)
Details
- External ID
- 45745059
- Source
- HN
- Company
- —
- Product
- Emotive Engine
- Website domain
- github.com
- Launched
- Oct. 29, 2025
- Cohort
- —
- Upvotes
- 6
- Upvotes percentile
- 0.3018867924528302
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:25 p.m.
- Updated at
- Sept. 7, 2026, 9:25 p.m.
Description
Hey HN! I'm the creator of Emotive Engine. I've been working on this for 2+ years and finally open-sourced it today.The core idea: Most animation libraries work in milliseconds. Music works in beats. This creates a mismatch - hardcode a bounce for 500ms (perfect at 120 BPM), switch to 90 BPM, and everything drifts because 500ms is now 0.75 beats.Emotive Engine uses musical time as the atomic unit. Specify animations in beats, and they automatically become: - 500ms at 120 BPM - 667ms at 90 BPM - 353ms at 170 BPMChange tempo, everything adjusts. No recalculation needed.Built for AI interfaces (chatbots, voice assistants) but works for any real-time character animation. Pure Canvas 2D, 60 FPS on mobile, 2,532 tests passing.Live demo at https://emotiveengine.com/demo - the hero banner on GitHub was generated with the engine itself.Happy to answer any technical questions! MIT licensed.
Enrichment
- Theme
- audio and music production tools
- Vertical
- Media & entertainment
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Commercial product
- Normalized one-liner
- animation engine with musical timing
- Manually corrected
- False
Could you build this?
Partial Building basic time-synced animations is approachable, but building a production-grade beat-driven animation timing engine with continuous tempo changes and audio-clock sync requires domain math.
What it would actually take: The library must be built in TypeScript/Web Audio API, implementing a transport timeline that syncs animation frames (requestAnimationFrame) to audio clock drift, musical quantization (ticks, PPQ), and dynamic musical tempo changes (BPM ramps). The hard parts are maintaining frame-accurate synchronization against audio context hardware clocks, handling complex polyrhythmic interpolations, and preventing visual jitter. This requires deep familiarity with digital audio workstation (DAW) transport architecture and animation timeline math.
Discussion
2 comments analyzed.
Competitors
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Attention rank: #105 of 127 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Looks like the first mover among its competitors.
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Other launches for this product
- No other launches for this product.
Same idea, different domain
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