Kevin,
Thanks for reminding me to check my OpenGL settings, they were set to low. You forget that the setting isn't saved from file to file unless you are using a saved template file. Increasing them and checking anti-aliasing helps but the nurbs surface still only shows as a curve in hidden line render.
Yes, you are correct about the top of the trusses being flat compared to the sloped roof. But if you look at the file from the right or left view in wire frame you will see that the roof surface is above the flat top of the trusses and they still show thru! I need to raise the roof surface nearly 2.75" above the trusses for it to not be visible in OpenGL? That seems like a very large gap, considering if the track that the roofing material slides into is 6", that a very large error to have in the file just to render correctly. Right now I'm in the rough layout phase, I should be able to look at the roof surface just touching the top of the trusses and then move it up 6" and know that later when I add the channels I don't have the same visualization problem all over again.
I guess I should submit the nurbs anomaly as a "bug" to be looked at.
Dennis
Kevin, I hope you don't mind me copying your footer, I thought it would provide some of the background operating parameters if that matters or helps.
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VW 2015 Designer w/Renderworks SP4 | Since Minicad 6 | Mac OS 10.10 | Retina Display Macbook Pro 8GB Ram |