public void AddPolylines( 
   IEnumerable<Polyline> polylines,
   TinSurfaceType tinSurfaceType,
   int tagValue,
   double z,
   SpatialReference spatialReference
)

{ 
  // Add polylines with tagValue = 42 and height = 12. 
  // The polylines are in a different spatial reference than the tin editor, so we provide the spatial 
  // reference of the polylines. The polylines will be projected to the spatial reference of the tin editor.
  Polyline[] polylines = new Polyline[] //Define some polylines
  {
    PolylineBuilderEx.CreatePolyline(new List<Coordinate2D>
    {
      new Coordinate2D(0,0),
      //...
    }),
    PolylineBuilderEx.CreatePolyline(new List<Coordinate2D>
    {
      new Coordinate2D(20,20),
      //..
    })
  };
  tinEditor.AddPolylines(polylines, TinSurfaceType.ZLessSoftLine, 42, 12, SpatialReferenceBuilder.CreateSpatialReference(54004));

  // Add z-aware polylines with no tag value. The height comes from the z-values of the vertices. 
  // The polylines are in the same spatial reference as the tin editor, so there is no need to provide it.
  Polyline[] polylinesZ = new Polyline[] //Define some z-aware polylines
  {
    PolylineBuilderEx.CreatePolyline(new List<Coordinate3D>
    {
      new Coordinate3D(0,0,5),
      //...
    }),
    PolylineBuilderEx.CreatePolyline(new List<Coordinate3D>
    {
      new Coordinate3D(20,20,15),
      //..
    })
  };
  tinEditor.AddPolylinesZ(polylinesZ, TinSurfaceType.HardLine, 0);
}