Agent Skills: UI useFrame

UI useFrame

Sync UI elements outside the Canvas with the render loop using R3F v10's external useFrame.

Technique

Since React Three Fiber v10, useFrame can be used outside of the Canvas component. This allows updating DOM elements in sync with the 3D scene without using Drei's Html component.

Key Concepts

• useFrame works outside <Canvas> in R3F v10+
• Use refs to manipulate DOM elements directly for performance
• Throttle with { fps: N } option since DOM manipulation is expensive
• Useful for HUDs, debug info, and UI that doesn't need to be in 3D space

Usage

const Ui = () => {
  const ref = useRef<HTMLDivElement>(null)

  useFrame(() => {
    ref.current.innerText = `${position.x.toFixed(2)}, ${position.y.toFixed(2)}`
  }, { fps: 10 })

  return <div ref={ref} className="fixed top-4 right-4" />
}

// Place outside Canvas
<Canvas>
  <Scene />
</Canvas>
<Ui />

This skill is part of verekia's r3f-gamedev.