Quality of image created by V3d_View::ToPixMap() is pretty low

Using V3d_View::ToPixMap() + Aspect_PixMap::Dump() is the most acceptable and
reliable way for creating 3D view snapshots in OCC-based applications. The main
advantage of this approach is that it does not put pieces of overlapping
windows to an image (while V3d_View::Dump() does) and also allows to add any
additional textual or graphical data to the image before saving it to a file.

However, there is a problem concerning line fragments representation in an
image when 3D scene contains touching or overlapping lines and shaded areas.
Unfortunately, IN A RESULT IMAGE pixels belonging to such line fragments are
partially or completely covered by pixels belonging to shaded areas while the
3D scene looks pretty well ON THE SCREEN (just compare attached pixmap.bmp
obtained by means of ToPixMap() method to Attachment 2 (BMP) created with help of Dump()).

Obviously, this drawback makes this approach hardly suitable for commercial
applications.

Therefore, it would be extremely desirable to investigate and possibly
eliminate the source of this problem.