Thanks Kix for clarifying Shonner's post. It is pure done in Carrara using VM and its own primitives. I could not find any function to switch polygon back to grey from blue. Basically I put a sphere in the VM room from primitive toolbar and turned it into smooth in subdivision in selection window. Then I use the cease/smooth and clicked on polygons to get the flat effect. I decided to turn polygons back to smooth using double-click with crease/smooth but it didnt happen. It kept the blue polygons infinitely.