I extract a lot of curves form 3D models for CNC milling. A lot of the times I get these curves from the left/right/bottom viewports. But then I have to nest these curves onto sheets of material, so I need them all in the same viewport oriented correctly.

Is there a function, shortcut or alias for that following situation?

You could make a little script for it, that gets the planes of the planar curves and then does a plane/plane transform to your top viewport. Does the orientation matter? The plane of the curve can be in two directions so the curve might end Z up or Z down

import Rhino
import rhinoscriptsyntax as rs
def orient_curves():
"""
example to orient planar curves to world XY plane
"""
curves = rs.GetObjects("select curves to orient", 4)
if not curves:
return
new_curves=[]
for curve in curves:
plane = rs.CurvePlane(curve)
if plane:
transform = Rhino.Geometry.Transform.ChangeBasis( Rhino.Geometry.Plane.WorldXY, plane)
rs.TransformObject(curve, transform)
new_curves.append(curve)
for curve in new_curves:
#align curves left
bb = rs.BoundingBox(curve)
trans = -bb[0]
rs.MoveObject(curve, trans)
while len(new_curves)>0:
#spread the curves
bb = rs.BoundingBox(new_curves[0])
trans = bb[1]-bb[0] +Rhino.Geometry.Vector3d(5,0,0)
new_curves.pop(0)
rs.MoveObjects(new_curves, trans)
orient_curves()