hey mike, timberwrestler is right. Cadwork.
to drive the timber dimensions, you just go into a 2-d plane and select beam, chose width and height (or depth) and select reference points.
here is the plan and perspective I have come up with. light roof. every X-section need not be gargantuan.
p.s. just gotta fix that rafter spacing.
thanks fellas,
Moyer