Is fx required while building collada on Linux?

Hi,
I was trying to compile Collada-Dom on Ubuntu.For this i downloaded collada-dom-2.2.zip and compiled the same as per the instructions given on
http://www.openscenegraph.org/projects/osg/wiki/Support/KnowledgeBase/Collada” for linux.
But when i do "make os=linux project=minizip " the compiler compiles for
“make os=linux project=minizip -C dom” and “make os=linux project=dom -C dom” but throws an error for make os=linux project=fx -C fx.
Also it gives an error saying that Cg/cg.h: No such file or directory.
So just wanted to cross check if fx and Cg are really required.If yes,for what purpose are they required.

Regards,
Siddhi

Can someone help me out with this.I need this information on an urgent basis.

You only need to build the dom project. The others are sample applications.