I know how to do it, but I need to know how big is the architecture and the environment.
I supose there ara no refractions, water, and other things that need special fx in unity or unityPro.
Other aspect, is the sky, Do you have environment images such as kybox?
Vray renderizes very nicely and if you want to unity's version to have the same aspect, I will have to bake illumination as textures for every object in the scene... it makes it a long and meticulous task...
A.