I've ran into this issue several times and haven't figured out a quick/easy way to do it.  Basically, I have a thin/flat structural panel that I want to put lightening holes in, but in a truss-like pattern.  In the past, I've just done in using cut-extrude, but the sketches get nasty once you get a complicated pattern (or repeated pattern).  It seems like you should be able to just draw lines to represent the center of the truss elements, and Solidworks will do the rest.  Sort of like creating ribs.

So, going from this:

To this:

This is a very simple example, but you get the idea.  How would you do this?  It seems weldments might do the trick, but I'm not totally sure and couldn't get it to work.

Any help would be appreciated!

Thanks!