"Sphere (Surface)" node: add NURBS option.

1e660f6f · Ilya Portnov · 21376efa · 1e660f6f · 1e660f6f
--- a/nodes/surface/sphere.py
+++ b/nodes/surface/sphere.py
@@ -7,7 +7,8 @@ from bpy.props import FloatProperty, EnumProperty

 from sverchok.node_tree import SverchCustomTreeNode
 from sverchok.data_structure import updateNode, zip_long_repeat, ensure_nesting_level
-from sverchok.utils.surface import SvLambertSphere, SvEquirectSphere, SvGallSphere, SvDefaultSphere
+from sverchok.utils.surface.sphere import SvLambertSphere, SvEquirectSphere, SvGallSphere, SvDefaultSphere
+from sverchok.utils.surface.algorithms import build_nurbs_sphere

 class SvSphereNode(bpy.types.Node, SverchCustomTreeNode):
    """
@@ -22,7 +23,8 @@ class SvSphereNode(bpy.types.Node, SverchCustomTreeNode):
        ('DEFAULT', "Default", "Based on spherical coordinates", 0),
        ('EQUIRECT', "Equirectangular", "Equirectangular (geographic) projection", 1),
        ('LAMBERT', "Lambert", "Lambert cylindrical equal-area projection", 2),
-        ('GALL', "Gall Stereographic", "Gall stereographic projection", 3)
+        ('GALL', "Gall Stereographic", "Gall stereographic projection", 3),
+        ('NURBS', "NURBS Sphere", "NURBS Sphere", 4)
    ]

    def update_sockets(self, context):
@@ -79,8 +81,12 @@ class SvSphereNode(bpy.types.Node, SverchCustomTreeNode):
                    surface = SvEquirectSphere(np.array(center), radius, theta1)
                elif self.projection == 'LAMBERT':
                    surface = SvLambertSphere(np.array(center), radius)
-                else:
+                elif self.projection == 'GALL':
                    surface = SvGallSphere(np.array(center), radius)
+                elif self.projection == 'NURBS':
+                    surface = build_nurbs_sphere(np.array(center), radius)
+                else:
+                    raise Exception("Unsupported projection type")
                surfaces_out.append(surface)
        self.outputs['Surface'].sv_set(surfaces_out)


--- a/utils/surface/algorithms.py
+++ b/utils/surface/algorithms.py
@@ -1376,3 +1376,13 @@ def remove_excessive_knots(surface, direction, tolerance=1e-6):

    return surface

+def build_nurbs_sphere(center, radius):
+    vectorx = np.array([0.0, 0.0, radius])
+    axis = np.array([0.0, 0.0, 1.0])
+    normal = np.array([1.0, 0.0, 0.0])
+    matrix = SvCircle.calc_matrix(normal, vectorx)
+    matrix = Matrix.Translation(center) @ Matrix(matrix).to_4x4()
+    arc = SvCircle(matrix=matrix, radius=radius, normal=normal, vectorx=vectorx)
+    arc.u_bounds = (0.0, pi)
+    return nurbs_revolution_surface(arc.to_nurbs(), center, axis, 0, 2*pi, global_origin=True)
+