BUG: Fix scaling of 3D window snapshots
Slicer svn revision 24668 incorporates a fix for a bug in vtkRenderLargeImage so it now works with gradient backgrounds. Use this class to do off screen magnified rendering of the 3D window when capturing screen shots.
A bug still remains for the 2D windows in that they get tiled by this method instead of scaled, so continue using the Qt after capture scaling for the full view and the slice views.
Issue #3885