Chaotic terrain

[Mahnmut]

Could be Mars, could be Morocco.
The rockshapes are closely based on Seth93s "Grainy dusk" tgd, thanks a lot!
The rest is mine. I like the ripples in the dust.
No sense of big scale intented.
What do you think about the sky?
I thought this could be a nice solution for the much discussed redsky/bluesky problem. 180 degrees from the sun this sky ist pure blue, haze glow makes it "classical martian".

[rcallicotte]

I like it and wonder if soft lighting was on.  Might make it better.  I like the terrain and the lighting is good as far as the color.  Good perspective.  Shadows might need some soft lighting.

[Mahnmut]

Thanks Calico.
Soft shadows are turned on with .6 meters, 9 samples. the big stones are 5 meters in diameter.
I am wondering why the shadows aren´t softer myself.
Is it that what you mean by soft lighting?

[rcallicotte]

Yes, soft shadows.  What are your settings for contrast and gamma correction under the Render / Effects tab?  Maybe you need to play with those values a little, but I'm surprised if their set to the default.  What are your Enviro light settings?  Did you use any GI?  Maybe that would help...though it's likely GI Surface Details doesn't need to be checked, some GI would help...maybe a little more.  Hard to know without working on it.   

[dandelO]

The thing to remember with soft shadows is that they're scale dependant, if the rock in the foreground was actually a couple of metres wide in scale then your .6m shadows would look great, if however, and I assume this is the case, the rock is very large and the images' overall scale is making me think the rock looks about a couple of metres wide then, you need to really up the soft shadow diameter significantly, depending on the actual scale obviously, try moving the diameter up by increments of 1 meter at a time and crop rendering that portion until you notice a real softening of the shadow's edge.

I like the image though, very nice sand.

[dandelO]

the much discussed redsky/bluesky problem

What's this?

[Mohawk20]

the much discussed redsky/bluesky problem

What's this?

I guess a reference to the discussion if the Mars atmosphere it blue or red.

[Mahnmut]

@Calico:
Contrast is on default, gamma was 2.0, now it´s 2.1, looks good on my screen but to dark on most flatscreens I fear.



Set soft shadows to 1.5 metres now.

GI is at 2/1, more takes quite long, I will try that if I can afford a new computer.
@dandelO: The biggest rock in view has a  diameter of 5 meters, the feature scale of the little dunes is 0.75 m. The haze density is 9, so everything further away would not appear that clear. this image is meant to show a region with very short views, thus the title chaotic terain.
Your assumption makes sense, but its not it.
I have no idea why the shadow is still that sharp even at 1.5 m.

Redsky/bluesky:

http://www.redicecreations.com/article.php?id=263

it´s not the most serious source, but the first I found.
I don´t know if my solution is realistic, but I like it. Its a bluesky with a density of 0.75 and haze density 9 , same colour as the dust on the ground.

[Mr_Lamppost]

I have no idea why the shadow is still that sharp even at 1.5 m.

Because the Soft Shadow Diameter is measured in degrees.  The default 0.5 is approximately correct for the sun or moon as seen from the Earth's surface. 

Remember that the soft shadow calculations apply only to the primary rays coming directly from the sun.  Forward scattering from the atmosphere or the glow from thin clouds is not included in shadow calculations. 


If a Light Source is used then the softness of the Soft Shadows is controlled by the Source Radius which is measured in metres.

[Mahnmut]

@ Mr. Lamppost:
Does that mean for a clear day on Mars I needed more or less half as much, (which wouldn´t make much difference like my 1.5) while for venusian lighting conditions, which have been compared to a rainy day in Moscow I should set it to 180 because the whole sky is the light source?
I´ll try with ten then, could match my clouds.
Thanks, I didn´t understand that value until now.
Good night.

[dandelO]

Because the Soft Shadow Diameter is measured in degrees.

Cheers Mr. L.
I assumed(insert dandelO's an ass gag) that the sun's normal shadow's hard edge, without soft shadows, was the equivalent of '0 metres diameter' and as the diameter is increased, say to 2, then that would mean the '0' point was the central point between the gradient from full shadow to no shadow, in other words, a metre on either side of the hard edge for a shadow diameter level of 2.

[Mr_Lamppost]

The idea of the soft shadow being a little bit either side of the zero, hard shadow line is right, but the divergence is measured in degrees.  That way the softness of the shadow is dependent on the distance between the object and the surface onto which its shadow is cast.   Look at the shadow cast by a lamppost or telegraph pole on a sunny day when the sky is clear.  Close to the bottom the shadow is sharp and well defined, this is because the distance between the shadow and the part of the object casting it is small. Now look at the shadow cast by the top of the pole or lamp if you are using a lamppost, the shadow is soft and less well defined, small details in the shape are blurred and lost, this is because the distance between the object and its shadow is greater. 

Astronomy sites should be able to provide the angular diameter of the sun as it appears from different planets.  Failing that, the diameter of the sun is a known quantity so it is a bit of simple trigonometry to work out its apparent angular at diameter at any given distance. 

For Venus I would just use high GI settings as all the light reaching the surface is diffused by the clouds. 

[Matt]

What Mr_Lamppost said

Matt