func get_nurbs_B() *gm.Nurbs { verts := [][]float64{ {5.0, 10, 0, 1}, // global 0 {8.0, 10, 0, 1}, // global 1 {8.0, 13, 0, 1}, // global 2 {5.0, 13, 0, 1}, // global 3 {6.0, 11, 0, 1}, // global 4 {6.0, 12, 0, 1}, // global 5 {7.0, 11, 0, 1}, // global 6 {7.0, 12, 0, 1}, // global 7 } knots := [][]float64{ {0, 0, 0, 0.5, 1, 1, 1}, {0, 0, 1, 1}, } ctrls := []int{ 0, 4, 6, 1, // first level along x 3, 5, 7, 2, // second level along x } var nurbs gm.Nurbs nurbs.Init(2, []int{2, 1}, knots) nurbs.SetControl(verts, ctrls) return &nurbs }