Do you guys know some plugin to sketchup, which is free, and which have similar funkcion like SubdivideAndSmooth?

helo guys, I have just started with hypershot, and i have got big problem using it, so I hope, that somebody can help my......The problem is, that I just cannot have more than one texture in one model.....? For example, when I have house, and I add some material on roof, than whole house is covered with this material, not just roof, and then, if I add trancusclent glass to windows, than is house trancusclent at all......? What am i doing bad?

Hello, I am new here, but I am trying to work with sketchup longer time. Now, I have decided to try work with rendering on sketchup models......Can somebody tell me, which free render program is easiest to use?