轴对齐包围盒(AABB)

//获取点集的包围盒
CGAL::Bbox_3 bbox = CGAL::bbox_3 (points.points().begin(), points.points().end());
//获取Mesh的包围盒
CGAL::Bbox_3 bbox = CGAL::bbox_3(mesh.points().begin(), mesh.points().end());
//取值
auto xmax = bbox.max(0);
auto ymax = bbox.max(1);
auto zmax = bbox.max(2);
const double z_range = bbox.max(2) - bbox.min(2);