facets in rendering

[tiatia]

Bye to all,
I press that I am a new member and therefore apologize in advance if I have to wrong something; I have a problem with autocad architecture 2012, in the sense that with this program I create the model using parametric objects and, when I made a try to make to check if there was something wrong, I found facets on the walls (see photo).....my question is, why does it do so? What can you do to eliminate the problem? ? ?
eternally grateful with those who will give me advice, greeting and wish good day! !

 

[Tristan]

You can't see anything. .

 

[tiatia]

I apologize, actually when I attach an image I realized that it resizes (maybe I mistake something boh..), however I attach it other where you see a little better.... .

 

[Tristan]

excuse but... what material is applied to the outer layer of the wall?

 

[tiatia]

ah nobody..... is the standard of the parametric object

 

[tiatia]

That's the problem. .