BoxGeometry

const box = new BoxGeometry({
  vertexFormat : VertexFormat.POSITION_ONLY,
  maximum : new Cartesian3(250000.0, 250000.0, 250000.0),
  minimum : new Cartesian3(-250000.0, -250000.0, -250000.0)
});
const geometry = BoxGeometry.createGeometry(box);