what's the definition of that ?thanks

I am not sure to understand what you mean by "definition"?

But it is just a personal exercice to analyse how we can create opening in a surface, and what are the consequences. I drew only 3 because I think there are the most common but it is easy to imagine more exemple.

I hope I answer to your question :)

hi , actually i would like to add such a holes to my design here in the attachment , so how can i do that ,, thanks

From the way i see it, You'll have to do some work to patch up each surface. The projection will only work in 1 vector I believe. 

I think for the result you are expecting for, you should inspire from the page 82 of http://www.liftarchitects.com/storage/research/Grasshopper%20Primer...

And you create intersection between your surface and the tube...

Does it help you?

page not found ...

Try here.

http://www.liftarchitects.com/journal/2009/3/25/the-grasshopper-pri...

So? does it work?

no it's not ,, :(