dh, what mitcorb said, +1.
Re Rubies, scary, maybe, there are so many, and it can be hard differentiating between versions and working out which can be be useful to ones workflow, but dark, absolutely not.
Its too late in the evening for me now, but let me put a selection of rubies together for you tomorrow which will, I promise, free your sketchupmind and literally save hours of tedium better spent realising the goal.
baz.
(sometimes known as 'Big Bad Baz', you physic or what?)
ps: the seam(ing) problem: how about you post a simple example in su which you have proven in your renderer to be disrespectful, I bet you someone here will work it out.