group() {
	sphere($fn = 0, $fa = 12, $fs = 1, r = 5);
	multmatrix([[1, 0, 0, 0], [0, 1, 0, 12], [0, 0, 1, 0], [0, 0, 0, 1]]) {
		sphere($fn = 0, $fa = 5, $fs = 0.5, r = 5);
	}
	multmatrix([[1, 0, 0, 12], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
		sphere($fn = 0, $fa = 12, $fs = 1, r = 6);
	}
	multmatrix([[1, 0, 0, 12], [0, 1, 0, 12], [0, 0, 1, 0], [0, 0, 0, 1]]) {
		sphere($fn = 5, $fa = 12, $fs = 1, r = 6);
	}
}