The TypeScript example does feel a little weird. I've used this library successfully with React + TypeScript with the following pattern: const mesh = useRef<

The TypeScript example does feel a little weird. I've used this library successfully with React + TypeScript with the following pattern: const mesh = useRef<THREE.Mesh>(null); // mesh has type RefObject<THREE.Mesh | null> ... useFrame((): void => { if (mesh.current != null) { mesh.current.rotation.x += 0.01; } }); ... return <mesh ref={mesh} ... /> As others have mentioned, the ref will typically attach by the time a `useEffect` hook is called, but for safety it's nice to have the null check.