9

Diffuse Color 929
at render time, especially if the polygon becomes
non-planar via tr ansformation of its vertices. Such
transformation and certain other operations can,
incidentally , cause automatic rearrangement of a
polygon’s diagonals.
Diagonals on the default Cylinder primitive
Diagonals are normally invisible, but in 3ds Max
they appear as dashed lines w hen you use t he
Turn or Edit Triangula tion tool. U nlike edges,
diagonals cannot b e transformed, or acted upon
with tools like Chamfer. This is different from the
hidden edges in editable mesh/Edit Mesh objects,
which are actual edges and can be made visible,
transformed, and manipulated with any editing
tool.
Diffuse Color
Vase has a mapped diffuse color.
The diffuse color is the color tha t an object reflects
when illuminated by "good lighting," that is, by
directdaylightorartificiallightthatmakesthe
object easy to see.
When we descr ibe an object’s color in
conversation, we usually mean its diffuse color.
The choice of an ambient color depends on the
kind of lighting: for moderate indoor lighting it
canbeadarkershadeofthediffusecolor,butfor
bright indoor lighting and for daylight, it should
be the complement of the primary (key) light
source. The specular color should be either the
same color as the key light source, or a high-value
low-saturation version of the diffuse color.