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.
Design model with the same geometry but different topology: a two independent trimmed surfaces and b connected surfaces by a Boolean operation. In a, the isocurves of the separated surfaces are displayed in black and red, respectively. (Color figure online)
