Fix #4735 by falling back to native implementation.

utils/curve/freecad.py

@@ -11,6 +11,7 @@
 from sverchok.utils.nurbs_common import SvNurbsMaths
 from sverchok.utils.curve.core import SvCurve, UnsupportedCurveTypeException
 from sverchok.utils.curve.nurbs import SvNurbsCurve
+from sverchok.utils.curve.nurbs_solver_applications import interpolate_nurbs_curve
 from sverchok.utils.curve import knotvector as sv_knotvector
 from sverchok.utils.curve.primitives import SvLine, SvCircle
 from sverchok.utils.curve.biarc import SvBiArc
@@ -257,6 +258,11 @@ def build_2d(cls, degree, knotvector, control_points, weights=None):
         curve.buildFromPolesMultsKnots(pts, mults, knots, False, degree, weights)
         return SvFreeCadNurbsCurve(curve, ndim=2)
 
+    @classmethod
+    def interpolate(cls, degree, points, metric='DISTANCE', tknots=None, cyclic=False, logger=None, **kwargs):
+        curve = interpolate_nurbs_curve(degree, points, metric=metric, tknots=tknots, cyclic=cyclic, logger=logger)
+        return curve.copy(implementation = SvNurbsMaths.FREECAD)
+
     def to_2d(self):
         return SvFreeCadNurbsCurve.build_2d(self.get_degree(), self.get_knotvector(),
                     self.get_control_points(), self.get_weights())

utils/geom.py

@@ -160,6 +160,8 @@ def create_knots(cls, pts, metric="DISTANCE"):
             tknots = tknots - tknots[0]
             if tknots[-1] != 0:
                 tknots = tknots / tknots[-1]
+        else:
+            raise Exception(f"Unsupported metric: {metric}")
 
         return tknots
 

utils/surface/nurbs.py

@@ -1170,7 +1170,6 @@ def simple_loft(curves, degree_v = None, knots_u = 'UNIFY', knotvector_accuracy=
         raise Exception(f"Unsupported knots_u option: {knots_u}")
     if logger is None:
         logger = getLogger()
-    curve_class = type(curves[0])
     curves = unify_curves_degree(curves)
     if knots_u == 'UNIFY':
         curves = unify_curves(curves, accuracy=knotvector_accuracy)
@@ -1198,7 +1197,7 @@ def simple_loft(curves, degree_v = None, knots_u = 'UNIFY', knotvector_accuracy=
     src_points = np.array(src_points)
     src_points = np.transpose(src_points, axes=(1,0,2))
 
-    v_curves = [SvNurbsMaths.interpolate_curve(curve_class, degree_v, points, metric=metric, tknots=tknots, logger=logger) for points in src_points]
+    v_curves = [SvNurbsMaths.interpolate_curve(implementation, degree_v, points, metric=metric, tknots=tknots, logger=logger) for points in src_points]
     control_points = [curve.get_homogenous_control_points() for curve in v_curves]
     control_points = np.array(control_points)
     #weights = [curve.get_weights() for curve in v_curves]