lowest altitude clouds are black

[sardie]

Full renders result in dark/black clouds at the lowest altitude.  Wondering what I should increase to bring back some of the light in these clouds.
[attach=1]

I have three layers of clouds, arranged in the node tree by altitude (though I don't think this matters).

Using Easy Cloud:
Highest layer; 3500 alt, 1500 depth, 0.01 edge 0.15 density. Direct Light is modified by a PF
Mid layer; 3000 alt, 1500 depth, 0.2 edge, 0.2 density
Lowest layer; 2000 alt, 6000 depth, 2.5 edge, 0.5 density. Direct Light is modified by a PF

The odd thing is, in spot renders of these clouds look fine.

Cloud Quality (all) 1, I have not changed the Softness on the clouds.
I decreased the voxel count on the mid, high clouds and lowered the transition distance to 4 on all clouds.
GI Settings: cache detail 4 (i'm not using cache file but i turned it up as a test), sample quality 4, blur radius 8, cloud gi quality still/very high. I've toggled and tested GI surface details, it seems to improve from below which I expected.
Micropoly detail 0.5, AA 4
I've increased the albedo of the storm clouds to no change, the first example is the render of that test.

As i was writing this I considered that I have fully disabled the surface/terrain. Turning compute terrain and render surface (Planet node) and keeping surfaces visible is what i've done recently, but i'm not sure i trust the spot render now. [attach=2]

It also occurs to me that these low level clouds are not actually receiving much direct light to modulate, here is my PF, White is Unclamped. [attach=3]

I'm working without RTP at this point as the approximation seems to assume there's light on the clouds.  Turning the cloud quality down also seems to skew final results so i've left them high, which unfortunately makes my troubleshooting quite time consuming.

Thoughts on what to tackle next?

[bobbystahr]

Maybe post a .tgd so we all can look inside...sometimes something will jump right out in the cloud nodes when viewed in TG

[Oshyan]

Have you tried not modulating the Direct Light by a PF? Since this is a lighting issue that would be the first thing to try, for sure. It may be that you're just wiping out all the light with the data coming from your PF.

Your lowest layer extends to 1000 meters under the planet surface (altitude sets the mid-point, your cloud extends 3000m up and down from there). This *may* be affecting things even if you have turned off surface rendering, depending on how you have done it, though I am not sure. It's definitely the next thing I would try adjusting though. Set the depth of that layer to 4000 or less and see if it improves things.

I also wonder why you may have changed some other settings, such as transition distance. I wouldn't mess with it for now, put it back to the default if you're troubleshooting.

GISD should not have any effect on clouds, and the general GI settings (cache detail and sample quality) are of less import here, I believe. In any case they're not likely the source of your issue.

If none of that helps, I agree with Bobby, seeing a TGD would be helpful for further troubleshooting.

- Oshyan

[Matt]

Your lowest layer extends to 1000 meters under the planet surface (altitude sets the mid-point, your cloud extends 3000m up and down from there

That's not true with Easy Cloud. Altitude is set by base altitude.

Matt

[Hannes]

Your lowest layer extends to 1000 meters under the planet surface (altitude sets the mid-point, your cloud extends 3000m up and down from there

That's not true with Easy Cloud. Altitude is set by base altitude.

Matt

That's good to know!!

[Hetzen]

Your lowest layer extends to 1000 meters under the planet surface (altitude sets the mid-point, your cloud extends 3000m up and down from there

That's not true with Easy Cloud. Altitude is set by base altitude.

Matt

That's good to know!!

That's also true for Get Position in Texture when using with cloud layers, the texture origin defaults Y=0 to the Base Altitude.

[Matt]

That's also true for Get Position in Texture when using with cloud layers, the texture origin defaults Y=0 to the Base Altitude.

For Easy Clouds, yes, because the localisation centre is at the base of the cloud. For other cloud nodes the localisation centre is halfway between top and bottom for backward compatibility. I should also point out that if "move textures with cloud" is turned off then Get Position in Texture is the same as Get Position, i.e. it's in world space.

Matt

[sardie]

Sorry I took a few days off of this.  I'm not certain I can share the files, unfortunately.  But if it comes to it I can just start fresh after I understand what's wrong.

I wanted to ask about altitude though. I am using easy cloud and I want to confirm I understand the way the clouds are distributed in the sky. I made this in excel because it was the easiest way for me to visualize the cloud altitude and depth.

[attachimg=1]
If this is right, perhaps the lowest layer is black because the clouds are intersecting with each other cloud layer?

Post script updates on what I've tested; I did redistribute the clouds based on the previous suggestion in this thread. I've also removed all PF connections from any cloud layer and I get the same results. I have turned on compute terrain & surface as well with some visible change on the underside of the clouds (minorly brighter) but the clouds were still black. And I increased the Softness in all clouds to 5-8 and there was some improvement but at 8 it was still very dark and it wasn't a fluffy cloud anymore it was odd, more light in some areas (wavey?) and still other black clouds elsewhere.

Update:
Redistributed High & Mid so that no cloud layer is intersecting.  (High 8600 base altitude and Mid 6750 base altitude) They get close but do not touch.  Lowest altitude clouds are still dark.

Update2:
I resorted to a sort of node debugging, I created a default easy cloud and I'm slowly replacing the modified properties until it breaks.  But any thoughts on what I've written before would be read/absorbed/appreciated

[Matt]

If they are Easy Clouds with base altitudes of 5000, 3500 and 500 (you didn't specify), then yes that is correct.

I hope you can narrow it down to a specific setting that's causing the blackness.

Matt

[bobbystahr]

Or maybe post a .tgd of the project minus anything you aren't allowed to share as we are more able to diagnose a problem when we can actually see what's happening from the guts level.