Wow !!! Oo
Thank you all !!!
It really took ridiculous proportions 
Here’s a small “breakdown” image that show how I made the grounds in the last scenes.
://tof.canardpc/preview2/af27cb52-a55c-41a2-bd07-22414b7d4e67.jpg
For the rendering part, well, I don’t really know what to say.
The setup is really basic :
- atmospheric fog : default parameters (with colors change according to the mood)
- exponential height fog : default parameters
- movable directional light : default parameters with different value for intensity and temperature according to the mood
- movable skylight : I just change the sky distance threshold to 1 and uncheck the low hemisphere is black (so I get some fake “bounce light” from the ground)
- postprocess volume : I use the new tonemapper (r.TonemapperFilm 1) and make some color correction with the new “color grading” section of the post process volume (no lut time)
- camera : I use the new “circleDOF”
And that’s all, no lightmap, no dfao/gi, no lpv. With a very simple scene you don’t really need , but more complexe your scene is more you need kind of stuff (especially good sky occlusion for exterior).