curvature_at now returns a tuple with all the info Rhino generates

Author: nmaslarinos

src/compas_rhino/geometry/surfaces/surface.py

@@ -186,12 +186,23 @@ def curvature_at(self, u, v):
 
         Returns
         -------
-        :class:`~compas.geometry.Vector`
+        tuple[[float, float, float], [float, float, float], float, [float, float, float], float, [float, float, float], float, float] | None
+            A tuple containing the point, normal vector, maximum principal curvature value, maximum principal curvature direction, 
+            minimun principal curvature value, minimun principal curvature direction, gaussian curvature value and mean curvature
+            value for the point at UV. None at failure.
+        
 
         """
         surface_curvature = self.rhino_surface.CurvatureAt(u, v)
-        vector = surface_curvature.Direction(0)
-        return vector_to_compas(vector)
+        if surface_curvature:
+            point, normal, kappa_u, direction_u, kappa_v, direction_v, gaussian, mean = surface_curvature
+            cpoint = point_to_compas(point)
+            cnormal = vector_to_compas(normal)
+            cdirection_u = vector_to_compas(direction_u)
+            cdirection_v = vector_to_compas(direction_v)
+            return (cpoint, cnormal, kappa_u, cdirection_u, kappa_v, cdirection_v, gaussian, mean)
+        else:
+            return None
 
     def frame_at(self, u, v):
         """Compute the local frame at a point on the curve.