Water shader luminosity?

Started by Moodles, February 29, 2020, 10:11:46 PM

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Moodles

Hey all,

I'm trying to get darker greener oceans, I've set the water shader to 0% opacity, volume density to 100 and volume colour to an off-black green. That went some of the way but made little change, so I added a default surface shader after that and played with the effects for ages with nothing, until... I lowered the luminosity to -0.1, that nets a much darker ocean with richer colours, but gets rid of the wave and wind patch effects. This is driving me nuts, what am I missing here, and if anyone knows a way to darken cloud shadows I'll be eternally in your debt. Just feels like everything is so damn bright and there's no real contrast. FYI deleted the envirolight and set it to 0 in the cloud layer too so it's not that unless there's one hidden somewhere else, I'm trying for an orbital shot similar to the attached

BYAydBUCcAA5Gsf.jpg

WAS

#1
Luminosity seems like an odd way to get darker green oceans, however experimenting randomly often leads to some interesting discoveries.

perhaps also your haze/blue sky is glowing so much you can't see the darkness of the water. If you disable your atmosphere, look how dark a default water shader is.

Your highlight spread also looks pretty extreme and it's outer most limits will add to lightening.

In summary, the ocean is so blue from orbit, because the sky is blue.

Matt

To get an image like this I would add contrast in post. I doubt that the original untouched photo looked like that. That highly saturated blue in the shadow is a result of pushing down the pixel values so that the red and blue are clipping (or nearly clipping) at black, while the blue channel retains some value. There are a number of ways of doing this, depending on what photo manipulation programs you use.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

To add also; as far as retaining the wind patches and such, you could use a glass shader and mimic the water shader, but use it's Roughness input to get some definition to the highlight. However having issues making the reflection look the same. I guess some sort of sacrifice would have to be made.

Attached an example.

Moodles

Spot on @WAS made a few little tweaks to the atmosphere and while not perfect, it looks a lot better, I did wonder about rendering out the ocean and clouds separately then combining them in post, so that could be an option.

@Matt thanks for the feedback, I think some post editing will be needed, but like you say it involves potentially clipping colours. Would it be possible in a future release to have a global control for how groups are rendered, such as shadow intensity, as well as an option to ignore rays/shading from other nodes, similar to C4D's composition tag? Would make art directing shots a lot easier. Or is there a way to tweak the strength of ray energy loss per bounce?
Apologies if any of this already exists, I'm still finding my way around.

Matt

#5
There are various ways that you can push the lighting in non-physical directions. For example, the atmosphere and cloud nodes have "Enviro light tint" which changes how they receive light from their surroundings (which predominantly affects their appearance in the shadows). Or you can do something similar but globally for all volumetrics by editing the Enviro Light's "Colour in atmosphere". There is a similar control for affecting the shadows on surfaces (Enviro Light "Colour on surfaces), but that only works in the Standard Renderer and is ignored when rendering with the Path Tracer (at least right now, v4.4).

Ignoring shadows and other rays from individual objects is possible, either by changing settings on those objects or by setting up Render Layers and controlling them per object group. With atmospheres and clouds you're a bit more limited, as you can't disable shadows without disabling other kinds of secondary rays such as reflections (as of v4.4, but this might change in future).
Just because milk is white doesn't mean that clouds are made of milk.