Imperative Updates

R3F does not ban imperative code. It gives you a cleaner place to put it.

Good Uses For Imperative Updates

• Animating values in useFrame.
• Updating camera targets or controls.
• Tweaking material or geometry properties that come from external systems.

Common Tools

• useRef to hold the object instance.
• useFrame for per-frame logic.
• useThree when you need access to shared renderer state like the camera, scene, or viewport.

const camera = useThree((state) => state.camera);

useEffect(() => {
  camera.position.set(0, 2, 6);
}, [camera]);

The Goal

Keep the scene shape declarative, then use imperative code in small, explicit islands for behavior that is naturally mutation-based.

External Resources

• React Three Fiber hooks docs
• Three.js Object3D docs
• React useEffect docs
• SBCODE: useEffect tutorial