There are utilities to smooth transition of materials. Go search.
LightWorks COULD HAVE GLOBAL ILLUMINATION in Archicad, but they will not implement it.
The closest thing you can do is put in a sky object and some extra suns and boost your ambient levels and boost your ambient reflections in materials.
Sigh.
In fact, give up on LightWorks and just get Artlantis. I think that Artlantis 2, even though it is weak in the materials area has strong lighting solutions and has about a two day payback on the investment. Okay. For you, maybe three. I was worried about the file transfer issue but it works pretty good now as long as you have the presence of mind to remap Artlantis changes in Archicad before updating the model export.
Get the demo. Make your renderings a bit taller to allow for cutting the logo off the bottom and Alfonse is your Mother's cousin.
Dwight Atkinson