Ruins

[Hannes]

I found this nice (and free) photogrammetry model of the Peirene fountain in Corinth/Greece:
https://sketchfab.com/3d-models/peirene-fountain-corinth-greece-0e27dbeb0aec4ed9a5a4e56a7d1c1e94

I made a very primitive bumpmap (just a B/W version of the actual texture map) and did some tests with sunny weather conditions which looked nice, but I eventually tried my hollow hemisphere method to get a nice overcast look, which looked a bit more interesting to me. I added some bushes using a map as distribution mask (I extracted the green areas of the original texture map and made them white and the rest black).
I also decided to create some puddles to make it look as if it had rained a lot during the last days. Additionally I used a color adjust shader to make the wet areas of the ruin darker.

[Tangled-Universe]

Looks really cool Hannes  
I like that you added water in the scene as I think ruins often get flooded and this gives it a realistic touch.
The water is a bit clear though? After fresh rain dust is mixed into the water giving it a muddy look and as water settles in the ruin, as it cannot be drained, the water will still look a bit muddy.
What you could try is adding some algae/slime/crap layer on the ruins which are under water? If you play with the colours of that layer and with water decay colour being different you can get very interesting effects.
Else I think you did a terrific job and it's really nicely rendered and post-processed.
Can you tell me where I can read more about your hollow hemisphere method?

[Kadri]

Looks good Hannes.

[Hannes]

Thanks for your comments, guys.
Martin, yes, I thought about adding some algae and stuff like you said. I'll see, what can be done.

My method is fairly simple. I place a hollow hemisphere over my scene, uncheck "cast shadows" and apply a selfilluminating white color to it (or an image map if you like). After I have disabled the sun I adjust the value of selfillumination until it's bright enough. Makes a nice overcast type of light, and as far as I can tell, it renders faster than a real overcast sky with real clouds.
This all looks best with the path tracer!!!!

[Dune]

Wow, this is really cool! Inspirational!

[Hannes]

A little bit more murky water, but not too much and some greenish algae stuff. It's very subtle, but I didn't want to exaggerate here.

[Tangled-Universe]

Very nice Hannes!
And thanks for explaining the hemisphere method.
Do you think this would also work with the background node inverted?

[Hannes]

Thanks, Martin!!
I don't know. Is the background something like a hemisphere? Maybe it's worth a try. Tomorrow...

[cocateho26]

Honestly if I didn't already know this was a render I wouldn't have guessed.

[DocCharly65]

That is very nice and so cool!

[mhaze]

Excellent.

[Hannes]

Do you think this would also work with the background node inverted?

Actually it seems to be working, and it doesn't need to be inverted. Strange, that the result doesn't show up in the RTP. And besides it only illuminates terrain or object with the PT.

[Hannes]

Rendering with an imported hollow hemisphere seems to be faster than using the background node. Maybe because of the size. In my scene I used a hemisphere that just covers the area of the object, while the background sphere is larger than the planet.
It may not be a huge difference when you render at small sizes. Rendering at 800X450 px I had 8.34 minutes with the imported hemisphere and 9.56 minutes using the background node. But at higher resolution this might be a big difference.

[sboerner]

Amazing. How much manual editing on the foliage? Any?

[Hannes]

Thanks Steve! Manual editing? I guess I moved one or two instances of the population to cover some of the green stuff that was scanned with the ruin model (and looked nasty), if that's what you mean.