Three

• Create the scene, camera, renderer, materials, and assets synchronously when possible.
• Render from HyperFrames time, not wall-clock time.
• Listen for the hf-seek event and render exactly that time.
• Load models, textures, and HDRIs before render-critical seeking. Do not fetch them at seek time.
• Avoid requestAnimationFrame or renderer.setAnimationLoop as the source of truth for render-critical motion.
• Always set data-duration="<seconds>" on the root [data-composition-id] element. Unlike CSS/WAAPI/Lottie, the three adapter has no duration auto-inference — it only forwards time via hf-seek/__hfThreeTime, it doesn’t inspect your scene for an AnimationClip/AnimationMixer length. Without data-duration (and no GSAP timeline), the render engine has no way to know how long to capture and fails with “Composition has zero duration”. npx hyperframes lint errors on this (root_composition_missing_duration_source).

The adapter sets window.__hfThreeTime and dispatches new CustomEvent("hf-seek", { detail: { time } }) on each seek.

Basic Pattern

Loading Addons (GLTFLoader, OrbitControls, etc.)

For anything under three/addons/, use an importmap so bare specifiers resolve. The HyperFrames lint recognizes both this form and the inline +esm import above — pick whichever your composition needs.

Pin the three version in both entries to the same value. Mixing versions across the map and bare imports causes silent breakage.

Heavy Setup (Large Meshes, Shader Compiles)

The runtime already waits for textures/models queued through Three’s DefaultLoadingManager before publishing render-ready. It has no visibility into CPU-bound work you do yourself after assets load — building a large procedural mesh, compiling shaders, warming a pipeline. That work can leave the canvas blank for seconds after the runtime and player already say “ready”.

If your setup does this kind of work, register a promise on window.__hf.buildReady (declared-compute hold: runtime waits, player shows its loading state instead of a blank frame):

Register it synchronously, in the same script block that starts the build — same timing as DefaultLoadingManager, so the runtime’s first readiness check already sees it. Only do this for setup an adapter cannot see; render-critical seeking still comes from hf-seek, not this hold. The key must be unique within the composition — a second registration under the same key silently replaces the first, dropping its hold.

AnimationMixer Pattern

For GLTF or authored clip animation, seek the mixer directly:

If several mixers exist, seek all of them from the same time.

Good Uses

• Deterministic 3D objects, product spins, particles with seeded data, and shader plates.
• Camera moves derived from time.
• GLTF animation clips when assets are local and loaded before validation completes.

Avoid

• Using Date.now(), performance.now(), or clock deltas to update scene state.
• Leaving render-critical work inside a free-running animation loop.
• Loading remote models or textures at render time.
• Device-pixel-ratio dependent output. Pin renderer size and pixel ratio for video renders.
• Post-processing passes that depend on previous frame history unless you can reconstruct state from time.

Validation

After editing a Three.js composition:

Credits And References

• HyperFrames adapter source: packages/core/src/runtime/adapters/three.ts.
• Why data-duration is required here specifically (no auto-inference for this adapter): packages/core/src/runtime/init.ts (resolveAdapterDurationFloorSeconds) and the CSS/WAAPI/Lottie adapters’ getInferredDurationSeconds, which the three adapter deliberately does not implement.
• Three.js WebGLRenderer docs: https://threejs.org/docs/pages/WebGLRenderer.html (opens in a new tab)
• Three.js AnimationMixer.setTime() docs: https://threejs.org/docs/pages/AnimationMixer.html (opens in a new tab)