Nice one Doc! Lots and lots of detail (as usual).

I have to apologize to Paolo for blaming Reality and/or LuxRender for the troubles I've had with that Bubble Ship. Of course I couldn't let it rest, and just now I've found it's DAZ Studio that can do strange things to the .obj's you load in it. Actually just to be sure it wasn't that, I exported those parts that rendered black from DAZ Studio and opened them in MeshLab. Huh? Black??? indeed, inverted normals. SH*******T!

I then flipped the normals of those parts in MeshLab, reloaded them, and started a new render. BINGO! Nicely rendered surfaces for all parts.

There was more damage done to those parts other than inverted normals, but they were fine according to both MeshLab, NetFabb Studio and ZBrush before I loaded them into DAZ Studio! I don't know what DAZ Studio does to imported obj's, but it's not always for the best. Lesson learned!

Cheers!

Erik