three.js/examples/jsm/loaders/obj2/bridge/MtlObjBridge.d.ts

import {
	MaterialCreator
} from '../../MTLLoader';

export namespace MtlObjBridge {
	export function link( processResult: object, assetLoader: object ): void;
	export function addMaterialsFromMtlLoader( materialCreator: MaterialCreator ): object;
}