SketchUp allows the user to apply different materials to the Front and the Back of a surface.
Thea for SketchUp can use just a single material and reacts differently, based on how the materials have been applied to a surface in SketchUp.
If Thea for Rhino is not set as the Current Render, then Thea specific properties for lights, like Visibility, will not be available. You will also see a different dialog everytime you create a new Thea Material.
Presto AO by default uses Ambient Occlusion to illuminate the scene and the Diffuse Depth is set to zero (0), in order to have fast feedback. However, translucent materials need to have a Diffuse Depth value greater than zero for the translucency to take effect. In the following images you can see, the influence of the Diffuse Depth parameter on the model.