Hello Hans, thank you for your response.
Please could you explain the procedure?

Hello, I'm using Sweet Home 3D on Mac OSX Lion (CPU i7 2.4 GHz - Video: AMD Radeon HD 6770M).
Fantastic program, but .... rendering is really ugly, unrealistic. [:(]

After many tests this is the best that I get:
http://i.imgur.com/949CO.png
it is possible to improve the rendering?
thank you ...