I have textured scene and m_bitmap_table.BitmapCount() returns zero

Hi,
I have scene with two textured boxes and
CRhinoDoc::m_bitmap_table.BitmapCount() returns 0. Why?

Thanks,

Not all bitmap textures are embedded in the document. Many are just referenced by their filename.

Here is a sample that dumps the texture filenames to the command line.

https://github.com/mcneel/Rhino5Samples_CPP/blob/master/SampleCommands/cmdSamplePrintMaterialTextures.cpp

Thank you.