GLTFLoader BufferAttribute unable to reference directly in THREE.BufferGeometry.attributes[x] (Suggested Fix)

GLTF Loaders BufferAttribute cannot directly be used as references for THREE.BufferGeometry.attributes[x] such as position or THREE.BufferGeometry.index

Three.BufferGeometry requires attributes to be typed for example as Float32BufferAttribute or Uint16BufferAttribute

The fix is quite easy.

1. add a new Mapping dict for Buffers ( which currently doesn’t exist it seems this is old and hardcoded):

	const WEBGL_COMPONENT_TYPES_BUFFER_ATTRIBUTE_MAPPING = {
		5120: THREE.Int8BufferAttribute,
		5121: THREE.Uint8BufferAttribute,
		5122: THREE.Int16BufferAttribute,
		5123: THREE.Uint16BufferAttribute,
		5125: THREE.Uint32BufferAttribute,
		5126: THREE.Float32BufferAttribute,
	};

1. later in the GLTFLoader code replace the buffer attribute line with the following:

const bufferTypeLookUp = WEBGL_COMPONENT_TYPES_BUFFER_ATTRIBUTE_MAPPING [accessorDef.componentType];

bufferAttribute = new bufferTypeLookUp( array, itemSize, normalized );
// bufferAttribute = new THREE.BufferAttribute( array, itemSize, normalized );



//some ifs bellow


const bufferTypeLookUp2 = WEBGL_COMPONENT_TYPES_BUFFER_MAPPING[accessorDef.sparse.indices.componentType];

// bufferAttribute = new THREE.BufferAttribute( bufferAttribute.array.slice(), bufferAttribute.itemSize, bufferAttribute.normalized );
bufferAttribute = new bufferTypeLookUp2( bufferAttribute.array.slice(), bufferAttribute.itemSize, bufferAttribute.normalized );

could probably reuse the same lookup for both attribute constructions.

doing a proper commit and pull request would take me too much time so I just write it here for the dedicated developer to pick it up 😃

[donmccurdy]

Most three.js contributors are not dedicated maintainers. With very few exceptions, we are doing this for free on our own time. If you are not comfortable making pull requests that’s OK, but please respect our time in addition to your own.

There may be a misunderstanding here — perhaps you’re using TypeScript and it’s giving warnings and errors in some particular situation? See https://github.com/three-types/three-ts-types if so. But in any case, there is no requirement to use Float32BufferAttribute etc. We can’t see these errors, but if they’re coming from three.js itself we can fix them. Please share details full details to reproduce the issue (as in the issue report template) if that’s the case.

[donmccurdy]

Three.BufferGeometry requires attributes to be typed for example as Float32BufferAttribute or Uint16BufferAttribute

There is no such requirement – using a generic THREE.BufferAttribute with a typed array is normal. Are you seeing some particular error or warning that you’re trying to fix?