load(fileMap) {
		let rootFile;
		let rootPath;
		Array.from(fileMap).forEach(([path, file]) => {
			if (file.name.match(/\.(gltf|glb)$/)) {
				rootFile = file;
				rootPath = path.replace(file.name, '');
			}
		});

		if (!rootFile) {
			this.onError('No .gltf or .glb asset found.');
		}

		this.view(rootFile, rootPath, fileMap);
	}
Loads a fileset provided by user action.
@param  {Map<string, File>} fileMap