Displaying an Image Behind a 3D Scene in React Three Fiber

To display an image as a background behind your 3D model in a React Three Fiber setup, you have a few options. The issue with your current approach is that HTML content rendered via the <Scroll html> component will always appear on top of the 3D scene by default.

Here are some solutions:

Option 1: Use a Background Component Outside the Canvas

The simplest approach is to place the image outside the Canvas as a fixed background:

JAVASCRIPTCopied
export default function Home() {
  return (
    <div className='w-full h-screen relative'> 
      {/* Background image */}
      <div 
        style={{
          position: 'absolute',
          top: 0,
          left: 0,
          width: '100%',
          height: '100%',
          zIndex: 0
        }}
      >
        <img 
          src={'example.png'} 
          style={{ 
            width: '100%', 
            height: '100%', 
            objectFit: 'cover' 
          }}
        />
      </div>
      
      {/* Canvas with transparent background */}
      <Canvas 
        camera={{ position: [0, 0, 5], fov: 75 }} 
        className='w-full h-full'
        style={{ position: 'relative', zIndex: 1 }}
        gl={{ alpha: true }} // Make canvas background transparent
      > 
        <ScrollControls pages={3} damping={0.1}> 
          <ambientLight intensity={0.5} /> 
          <pointLight position={[10, 10, 10]} /> 
          <Scene /> 
          <Scroll html className='w-full'> 
            <ScrollContainer> 
              <h1>html in here (optional)</h1> 
              <h1 style={{ top: '100vh' }}>second page</h1> 
            </ScrollContainer> 
          </Scroll> 
        </ScrollControls> 
      </Canvas> 
    </div>
  )
}

Option 2: Use a Background Texture in the 3D Scene

If you want the background to be part of the 3D scene, you can use a textured background plane:

JAVASCRIPTCopied
import { useTexture } from '@react-three/drei'

function Background() {
  const texture = useTexture('example.png')
  
  return (
    <mesh position={[0, 0, -10]}>
      <planeGeometry args={[20, 20]} />
      <meshBasicMaterial map={texture} />
    </mesh>
  )
}

export default function Home() {
  return (
    <div className='w-full h-screen'> 
      <Canvas camera={{ position: [0, 0, 5], fov: 75 }} className='w-full h-full'> 
        <ScrollControls pages={3} damping={0.1}> 
          <Background />
          <ambientLight intensity={0.5} /> 
          <pointLight position={[10, 10, 10]} /> 
          <Scene /> 
          <Scroll html className='w-full'> 
            <ScrollContainer> 
              <h1>html in here (optional)</h1> 
              <h1 style={{ top: '100vh' }}>second page</h1> 
            </ScrollContainer> 
          </Scroll> 
        </ScrollControls> 
      </Canvas> 
    </div>
  )
}

Option 3: Use Environment Map

For a more integrated approach, you can use an environment map:

JAVASCRIPTCopied
import { Environment } from '@react-three/drei'

export default function Home() {
  return (
    <div className='w-full h-screen'> 
      <Canvas camera={{ position: [0, 0, 5], fov: 75 }} className='w-full h-full'> 
        <ScrollControls pages={3} damping={0.1}> 
          <Environment 
            files={'example.png'} 
            background={true} 
          />
          <ambientLight intensity={0.5} /> 
          <pointLight position={[10, 10, 10]} /> 
          <Scene /> 
          <Scroll html className='w-full'> 
            <ScrollContainer> 
              <h1>html in here (optional)</h1> 
              <h1 style={{ top: '100vh' }}>second page</h1> 
            </ScrollContainer> 
          </Scroll> 
        </ScrollControls> 
      </Canvas> 
    </div>
  )
}

The first option is likely the simplest for your use case, especially if you want the background to be a static image. The second and third options integrate the background into the 3D scene itself, which might be preferable if you want the background to interact with the 3D elements.