Building a 3D Product Configurator in Three.js — Lessons From 9 Client Deployments

Over the last year I shipped 9 production 3D configurators for polish manufacturers — pools, garage doors, saunas, pergolas, greenhouses, packaging, decorative lamps, terrace roofs, and light-boxes. Each one runs live on its own subdomain of my studio at grodev.pl . Some of the lessons were obvious in hindsight. Some cost me a weekend of debugging. Sharing the non-obvious ones here. 1. Draco compression is not optional for CAD-heavy models Manufacturers send you STEP or SolidWorks files exported to glTF . Raw output is 40–120 MB per variant. On 4G mobile that's a 20-second load with an empty white canvas. Draco compression brings that to 2–5 MB with no visible quality loss on product shots: import { GLTFLoader } from ' three/examples/jsm/loaders/GLTFLoader.js ' import { DRACOLoader } from ' three/examples/jsm/loaders/DRACOLoader.js ' const dracoLoader = new DRACOLoader () dracoLoader . setDecoderPath ( ' /draco/ ' ) // self-hosted, don't use CDN const loader = new GLTFLoader () loader . setDRACOLoader ( dracoLoader ) loader . load ( ' /models/pool-3.5m.glb ' , ( gltf ) => { scene . add ( gltf . scene ) }) Self-host the decoder — Google's CDN version added ~600 ms to first paint in my measurements. Copy node_modules/three/examples/jsm/libs/draco/ to your public/ folder. Tooling: gltf-pipeline -i model.glb -o model.draco.glb --draco.compressionLevel 10 2. Instancing beats individual meshes past ~200 objects A pergola with 40 louvres × 3 tilt positions × user color picker = 120 meshes updating on every frame. Naive approach tanks FPS to 12 on mid-range phones. InstancedMesh batches identical geometry into one draw call: const geo = new THREE . BoxGeometry ( 1 , 0.05 , 3 ) const mat = new THREE . MeshStandardMaterial () const louvres = new THREE . InstancedMesh ( geo , mat , 40 ) const dummy = new THREE . Object3D () for ( let i = 0 ; i < 40 ; i ++ ) { dummy . position . set ( 0 , 0 , i * 0.15 ) dummy . rotation . x = userTilt // update per frame is fine dummy . updateM