一个几何引擎库，国内用的较少。功能类似CGAL、NURBS++、OCC等。麻雀虽小，功能却很强大。尤其适合固体实体的建模。-A geometry engine library, domestic use less. Function similar to CGAL, NURBS++, OCC, etc.. Sparrows, though small, are extremely powerful. Particularly suita