Changing the materials of representations can dramatically affect images. The default material for 3D-SNFG is AOShiny; however, this can be easily adjusted with a function on the command line:

draw material Opaque

This command can either be input via the Tk Console, or the command line that opens with VMD. Note that the material can be changed to any that are listed in the Graphical Representations menu (i.e. Transparent, BrushedMetal, etc.).