Yes, your little dinosaurs are smart enough to get out of the rain, **if** it matters to them. Mine play in the rain all the time, by choice.
I'm fond of metal roofing, because it lasts longer and is lower maintenance overall - so twice the price (sure) but you only have to be hanging off your rafters and purlins once every other decade. I have an unhealthy fear of heights. Polycarbonate panels aren't so resilient (but are good for light - not a concern if you are only covering half the roof with solid panels, and you don't have solid walls).
That said, as you look at your roof halves, consider your prevailing winds - you don't want the underside of the roof you cover facing into your winds. Much better to have prevailing winds pushing into the top face of the roof, which will also assist in driving rain conditions to ensure a maximum of floor space stays dry.
I'm fond of metal roofing, because it lasts longer and is lower maintenance overall - so twice the price (sure) but you only have to be hanging off your rafters and purlins once every other decade. I have an unhealthy fear of heights. Polycarbonate panels aren't so resilient (but are good for light - not a concern if you are only covering half the roof with solid panels, and you don't have solid walls).
That said, as you look at your roof halves, consider your prevailing winds - you don't want the underside of the roof you cover facing into your winds. Much better to have prevailing winds pushing into the top face of the roof, which will also assist in driving rain conditions to ensure a maximum of floor space stays dry.