I've prepared a preset to achieve a similar result:
preset.zip (819 Bytes)
Here you are a couple of renderings done with it (thank you for the model):
The first one uses AmbientOcclusion (our rendering plugin for SketchUp) to generate an ambient occlusion layer. In order to use AmbientOcclusion together with SketchFX, you need to:
1- render the scene with AmbientOcclusion;
2- save the rendering as image;
3- create an Image Layer in SketchFX and load the ambient occlusion image;
4- set "multiply" as blend mode in the image layer.
We're planning an integration of AmbientOcclusion inside SketchFX to make this process easier.
Let me know if you need further assistance,