instancedBufferAttribute attach not working. What am I doing wrong?

[marcelpi]

Hi there,

I'm trying to use instancedBufferAttribute to set the position attribute of an instancedMesh.
Started from this sandbox, updated to @react-three/fiber 8 and updated the code to. I'm trying to use instancedBufferAttribute with the new attach API to set the geometry position.

<instancedBufferAttribute
  attach="attributes-position"
  count={positionArray.length}
  array={positionArray}
  itemSize={3}
/>

Still no geometry(spheres) are showing up. If I comment the instancedBufferAttribute and uncomment useEffect you can see how the scene should look like.

What am I doing wrong?

Here is the sandbox: https://codesandbox.io/s/react-18-attach-cdvgz6?file=/src/App.js

[pfarnach]

I'm a bit late but the code you're describing isn't in the sandbox anymore, maybe it was edited? What worked for me (to set the color) was to put the instancedBufferAttribute as a direct child of the instancedMesh, and then its attach prop as instanceColor. I set the position directly on the instanceMatrix via a ref but you can also set it via component, like here.