First off, id like to thank you for this program! You are quite talented sir and are creating an amazing utility!
It has come a long way!
Id like to add a feature request that I have... which is rather a large one to implement.
In general better viewport rendering.
More specifically, IF at all possible, shadows(perhaps with shadow maps?) , GLSL shader support(for realtime ambient occlusion and such), perhaps a more tweaked plastic shader,and perhaps adjustable light settings.
Just a few rough ideas for making the visual experience as enormously enjoyable as the building
The viewport visuals now are great dont get me wrong, but its more akin to a modeling program, it would be amazing if it could look a bit more like a final render.