If you have Softplan+ then you can export in multiple formats.
Have the 3D tab open, and click file, Softplan+ Publish, You will see 4 different options (Sketchup, Google Earth, Lumion FBX, STI).
I personally use Lumion for all Renderings. I find that Softplans 3D is a really good tool and LOD is very good, all the assets are very well made, can always tell that its a rendering compared to when I see it finished in Lumion.