Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The same faceted surface is shown rendered under two different illuminants. One contains a primarily diffuse illuminant (left) and the other, a diffuse plus a punctate illuminant (right). Note that the images differ substantially; in particular, the right-hand surface appears somewhat rougher.
