Direction along the vertical axis of letters of the text note.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)
public XYZ UpDirection { get; }
This vector points up from the base of the letters and is always perpendicular to the base direction. Those two vectors together define the plane of the text.