Not sure if this is just not way this is as I know Technical and Pen and possibly others are ‘special’ display modes but figured I’d ask anyway…
DisplayModeDescription dms = Rhino.Display.DisplayModeDescription.GetDisplayModes();
foreach (DisplayModeDescription dm in dms)
Bitmap b=Rhino.RhinoDoc.ActiveDoc.Views.ActiveView.CaptureToBitmap(new Size(100,100),dm);
does work but the bitmaps returned from the pen, technical display modes are either duplicates of wireframe or just background with no geometry.