Use the View tab > Appearance panel > Mesh options to shade meshes:
The following section is used to show the effect of the different buttons:
Nodes and open edges, hollow — Select this option to display nodes and open edges over hollow triangles:
Open and interior edges, hollow — Select this option to display open and interior edges over hollow triangles:
Nodes and open edges, shaded - Select this option to display nodes and open edges over shaded triangles:
Open and interior edges, shaded - Select this option to display open and interior edges over shaded triangles:
Open edges only - Select this option to show meshes as open edges only.