Terragen2 had to work hard and long to get this 1600x1200 one finished: 94:44:03. Detail 0.9, AA 6, GI sliders both at 2. A smaller render of 800x600 with detail set on 0.8 did render in 2:34:00.... I knew all these glass panels with their reflections would cause TG a headache but I didn't expect a full blown migraine!
I say glass panels but they actually are plane objects with a water shader for surface shader.
Not so happy with the localized cloud because at this scale it tended to look like a sphere.
Boat is by jedswindells from ShareCG, balloon is the Ele_balloon by gregsandor. The trees are the XFrog ones that came with TG2.
