In my last one, I wasn't happy with the 'cheap' way to do tile roofs. So this time, leveraging hidden layers in the clay tile component, I built a tile, and a ridge (top corner) tile for the roof, and an endcap. Then, while working in SketchUp, I only see a few layout lines of the tile, but when it renders in Twilight, it renders the full tile.
Here's the result... a SketchUp screenshot I will not likely be this close to the roof, but wanted to give it a good challenge.
Here's the full res of just the roof, no post pro (right-click>view image) Here's a reduced view of more context. about the corner stone quoins


About render times - definitely go UP with all these polys... there are over 4100 clay tiles, not counting the ridges and endcaps.
