3D shots

Three.js (live layer)

• Use threeLayer(el, { update(t), background, fov }) from /engines/three.js. Add an import map for three (see examples/engines-demo/index.html).
• update(t) sets every transform from t. Camera moves: keyframe with a GSAP tween on a plain object (tl.to(cam, { x: 4, z: 8, duration: 2 }, 3)) and copy it into camera.position in update.
• Models: GLTFLoader from three/addons/loaders/GLTFLoader.js (add "three/addons/": "/core/node_modules/three/examples/jsm/" to the import map). Wrap the load in Studio.wait(...). Put model files in the brand's assets/models/ or the production's composition/.
• The look (looks/README.md) decides the rendering style; the same model can go any of these ways:
  • Cartoon (looks/toon-3d): toon(color, { steps }) + outline(mesh, { thickness }). Hard light: one DirectionalLight + low AmbientLight.
  • Realistic (looks/photoreal): await realistic(renderer, scene) (wrap in Studio.wait: ACES tone mapping, a studio environment for reflections, soft shadows) + pbr(color, { metalness, roughness, clearcoat }). A key light with castShadow, a cool rim light from behind, a ShadowMaterial floor over a CSS gradient. Keep the camera above grazing angles (glossy faces turn white), move slowly, render the final with Studio.setup({ motionBlur: true }).
  • Neon (looks/neon-noir): emissive(color, intensity) + threeLayer(el, { post: bloom({ strength, threshold }) }), scene.fog. Keep threshold ≥ 0.2 and emissive ≤ 2 or everything blooms white.
• Animated GLB clips: create an AnimationMixer, then in update call mixer.setTime(t - start). Never mixer.update(delta).
• HTML tags that follow 3D points: in update(t), call camera.updateMatrixWorld() and the parent's updateMatrixWorld() before vector.applyMatrix4(obj.matrixWorld).project(camera). Three.js refreshes these only inside render(), so without it a tag follows the previous frame. Example: productions/bike-logger/REEL-002-engines.
• CAD meshes as JSON (vertices + indices): toNonIndexed() + computeVertexNormals() gives crisp flat facets. Render with threeLayer(..., { pixelRatio: 2 }) for supersampled edges.
• Physics: bake it (simulate at a fixed 1/120 s step into an array before the first frame) and look up by t.
• Talking character: load /engines/lipsync.js and the line's .visemes.js (from scripts/lipsync.sh) with classic <script> tags, then in update(t): LipSync.paramsAt(cues, t, "mouth", { offset }) → { open, wide, round } (0…1) onto morph targets (mesh.morphTargetInfluences) or a mouth mesh's scale. See engines/README.md, Lip sync.

Blender (plate)

• A scene script defines build(ctx); copy engines/blender/example_scene.py. ctx gives toon(rgb), key(obj, "location", t, value), size, fps, duration, frames, scene.
• Render: engines/blender/render.sh scene.py composition/plates/<name>.mp4 --size 1080x1920 --duration 4 [--engine EEVEE|CYCLES|WORKBENCH]. Draft at --size 540x960, final at full size.
• Backdrop colour: show it to the camera only (Light Path "Is Camera Ray" mix, as in the example), or it lights the scene and flattens toon bands.
• Colour management is set to Standard so brand hex colours come out as typed. For a photoreal plate, switch to ctx["scene"].view_settings.view_transform = "AgX" in build, render with --engine CYCLES, and use area lights and camera depth of field.
• Physics and simulations: bake them in the scene script before rendering.
• Talking character: import lipsync as L in the scene script (run.py puts engines/blender/ and the script's own folder on the path), cues = L.load("productions/…/audio/vo.visemes.json"), then L.key_shape_keys(head, cues, ctx, offset=VO_START) keys shape keys open, wide, round on every frame (names={"open": "Jaw"} for other names). Anything else: L.params_at(cues, t, offset=…) per frame with ctx["key"].
• In the composition: <video src="plates/<name>.mp4"> + Studio.video(el, { start }). Plates have no alpha; put text and characters on top with HTML layers.

Check

Render the key beats as stills and look at them. For Three.js, render one frame twice and compare md5s. Note render times in the production log.