Get size of object

[wongena]

Is there a way to get the size of an object loaded by the STL loader?
I loaded an object using the STL loader and want to get the size of it to resize another object in relation to the original's size.

const geomUpper = useLoader(STLLoader, upperUrl)

Is there a way to get the size of geomUpper using only react-three-fiber? Or do I need to use Three.js itself for that?

[drcmda]

fiber is just a renderer, you're still using plain threejs. but sure, three has a function for that:

function Upper() {
  const geomUpper = useLoader(STLLoader, upperUrl)
  
  useLayoutEffect(() => {
     const box = new THREE.Box3()
     box.expandByObject(geomUpper)
     const size = box.getSize(new THREE.Vector3())
     // ...
  }, [])
  
  return <primitive object={geomUpper} />

[wongena]

I have tried this code but now it says on the expandByObject line that 'object.updateWorldMatrix is not a function at Box3.expandByObject'. I red that this could happen because geomUpper, loaded by STLLoader is a JSON file containing data about the STL file or BufferGeometry and not a Object3D, Does three fiber have a loader that loads stl files as Object3D and not a JSON file or BufferGeometry?