ConstrainNormal behavior on morph

Is there a way to get ConstrainNormal=Yes behavior when using CRhinoSporphSpaceMorph in the c++ SDK ?
I see there is a m_N1 member to use alternatively to the target surface normal, but I’m unsure that’s it’s purpose or how I would set it to mimic the flow behavior like the Rhino app.

Hi @inetbob,

You’re spot on with the CRhinoSporphSpaceMorph::m_N1 member.

CRhinoSporphSpaceMorph sporph;
CRhinoView* view = RhinoApp().ActiveView();
if (nullptr != view)
  sporph.m_N1 = view->ActiveViewport().ConstructionPlane().m_plane.Normal();

– Dale