Clouds with no detail in shadows - very flat and dark shadow area in thick cloud

Started by D.A. Bentley, April 07, 2018, 09:43:47 pm

Previous topic - Next topic

D.A. Bentley

Looking for advice on how to deal with this common problem in Terragen. 

I am rendering with a 360 camera so I can't just pick a pretty portion of the clouds where the lighting works.  I need it all to look realistic in all directions.  Any tips/suggestions?

Another point to make, is I have no ground in my scene (not sure if reflected light from the ground would influence the clouds though).

[attachimg=1]

Oshyan

Reflected light *absolutely* influences the look of clouds. If you're having problems with dark undersides, this could be the problem. How did you disable the terrain from rendering? Depending on how you do it, you should be able to maintain the effect of the bounced light, even without the terrain actually rendering.

- Oshyan

D.A. Bentley

QuoteHow did you disable the terrain from rendering?

I just deleted the entire terrain and shaders branch/nodes.

QuoteDepending on how you do it, you should be able to maintain the effect of the bounced light, even without the terrain actually rendering.

I want to try that.  What settings would I use to keep the bounced light from a ground terrain/planet, but not have the terrain actually render?

Alternatively, would having a pretty thick lower layer of clouds at ground level also serve as a light bouncer?  If so, I'm guessing that would be more computational though.

While I wait for an answer, I'll get my terrain back in there, and do some test renders. 

Thanks,

Derek

bobbystahr

make the planet invisible to the camera I would think might work. don't have TG on this box so I can't check now.
I notice you can either turn off Render surface which gives the same results as Disabling the planet.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

AP

Clouds and Spherical Camera.

D.A. Bentley

Thanks AP!  Your scene tipped me off to something I didn't try.  Cloud Layer v3!

For some reason it's a lot easier to get the lighting looking good on Cloud Layer v3 clouds over v2.

I've been working with v2 clouds a lot since the presets I purchased all seem to use those old v2 clouds.

The Ground Plane did help reflect light, but I was still getting a mix of highly detailed clouds, with some very flat "cardboard cut-out" style clouds.

The interesting thing is a v2 and v3 cloud with the exact same Density Fractal produce completely different results.  I'll post some example renders later.

Thanks,

Derek

bobbystahr

Quote from: D.A. Bentley on April 09, 2018, 11:27:18 am
Thanks AP!  Your scene tipped me off to something I didn't try.  Cloud Layer v3!

For some reason it's a lot easier to get the lighting looking good on Cloud Layer v3 clouds over v2.

The interesting thing is a v2 and v3 cloud with the exact same Density Fractal produce completely different results.  I'll post some example renders later.

Thanks,

Derek


V 3 clouds were new and radically changed for TG 4 hence the difference. Seems that may be what you need. They do have a longer render time though so I still use Ver 2 for pedestrian and not hero clouds.
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

Oshyan

V3 clouds deal with internal light scattering inside clouds a lot better, so it's expected that there will be such differences even with the same input density shaders. Glad v3 is helping. :)

- Oshyan

D.A. Bentley

Here is a render comparison between a Cloud Layer v2 vs. v3 using the same Density Fractal.  These are rendered with a Terrain below, but I cropped that out since it was just a flat ugly surface.  It did take me 7 hours to render the original 4k top image (cloud layer v3), but I may have over done some settings unnecessarily.
[attachimg=1]

AP

Quote from: D.A. Bentley on April 09, 2018, 11:27:18 am
Thanks AP!  Your scene tipped me off to something I didn't try.  Cloud Layer v3!

For some reason it's a lot easier to get the lighting looking good on Cloud Layer v3 clouds over v2.

I've been working with v2 clouds a lot since the presets I purchased all seem to use those old v2 clouds.

The Ground Plane did help reflect light, but I was still getting a mix of highly detailed clouds, with some very flat "cardboard cut-out" style clouds.

The interesting thing is a v2 and v3 cloud with the exact same Density Fractal produce completely different results.  I'll post some example renders later.

Thanks,

Derek


You are welcome.

Oshyan

Strange, I wouldn't think it would be *that* different in terms of overall shapes. It could be explained by differences in default density interpretation, I suppose. But I would say that's a more extreme difference than I typically see.

- Oshyan

cyphyr

I too have found very little correlation between v2 and v3 clouds with the same cloud fractal plugged in. There should be some I would have thought.
www.richardfraser.co.uk
https://www.facebook.com/RichardFraserVFX/
/|\

Ryzen 9 3900X @3.79Ghz, 64Gb (TG4 benchmark 6:20)
i7 5930K @3.5Ghz, 32Gb (TG4 benchmark 13.44)

Oshyan

There definitely is *some*, in fact quite a bit, but the way v3 interprets density/edge profile is different. The actual fundamental shapes should be, well, the same. Although... this will vary depending on how Move Textures With Cloud is set, of course!

- Oshyan

D.A. Bentley

Still trying to figure out how "Move textures with cloud" works, or what it's used for.  Is there a simple explanation?

-Derek

Oshyan

It sets the cloud density function to move when the position parameters of the cloud layer are moved/changed, rather than keeping the noise function static and moving the cloud layer "through" it (which results in the cloud shapes of a given layer not remaining the same if you move the layer). However if it wasn't already enabled from the beginning, it does change the position of the noise function thus changing the shapes. You basically need to start with it enabled at the moment.

- Oshyan