ConstPlot.C		code to do constant shading of a Solid
ConstPlot.H
GouraudPlot.C		code to do Gouraud shading of a Solid
GouraudPlot.H
ps6-1.C			problem 1 framework
ps6-2.C			problem 2 framework
ps6-3.C			problem 3 framework
tgif_image.c		addition to tgif lib
SolidFace.C		rep for face of Solid (includes shading parameters)
SolidFace.H
Solid.C			rep for entire solid
Solid.H