Grainy image when rendering with clouds

[DVA99]

Hi,

I have been using TG2 for a few days now and I guess I have about 99% more to figure out about TG2.

The rendering result looked great in the beginning (not the images  ) but the result now is grainy or very grainy. Could it be due to the large and dense clouds?

Thanks for any help.

[Goms]

welcome!

try to set higher value for the atmosphere samples.
you can find this if you click on the planet atmosphere in the node network.
Select the quality tab and enter a value between 30 and 60 for this image (i guess).
this will increase render time, but remove the grain if the value is high enough.

try some crop renders and higher the value until you are satisfied

[DVA99]

Thanks for the advice Goms,

I tested to increase the quality and the cloud samples and the sunrays looks a bit better.

But, even with render quality of 1 and cloud samples at 128 it's not as good as the images I've seen in this forum.

It could be that I only have the TG2 free edition and can't increase the AA above 3. Guess I have to buy the "real" TG2

Thanks

[Goms]

try to increase the quality of the clouds also; this might help.

[Henry Blewer]

The haze value may help. I think the default value is 1. Try 2. Also use raytraced shadows in the atmosphere and clouds. This will increase the render time. Sometimes the atmosphere quality samples have to be set Very high. 256 may be enough.

[DVA99]

Thanks guys!

I'm rendering right now and the CPU fan sounds like a dustsucker on full speed 

I followed your advice and increased the cloud quality and the haze value.

Will let you know if this works or if the processor melts down.

Thanks

[DVA99]

Thanks guys!

The result after 1 hour looked much better. I can't even see the noise. But the rendering time with cloud samples of 128 for the atmosphere and the three cloud layers was too much.

So I tried to follow Oshyan's advice from 2009 about rendering. "if you see noise in the atmosphere try increasing the samples for the atmosphere".

So I decreased the samples for the clouds to 64 (12 for the cirrus 2d) and then 128 for the atmosphere.

It did the trick and the rendering time was about 10 minutes. I can live with that 

I attach the image (from another angle) which has lower settings than before except for the atmosphere.

Many thanks for all the help. It's an amazing software!

[DVA99]

Forgot to thank Goms.

If I had followed the advice from beginning about the atmosphere... I thought he meant the clouds.

Sorry guys, I'm a noob.

[Goms]

welcome

[Tangled-Universe]

Forgot to thank Goms.

If I had followed the advice from beginning about the atmosphere... I thought he meant the clouds.

Sorry guys, I'm a noob.

No problem at all to be a noob. We've all been there and have learned it in a similar way you're doing now. So feel free to ask.

May I add to this that it is best to always speak in terms of detail rather than samples in regard to clouds.
A detail setting value of 1 says much more than "I've used 128 samples".
For example:

Create a cloudlayer and set the detail-setting to 1.
Read the number of samples and keep it in your mind.
Now increase the cloud-depth 10x and increase cloud-density 10x.
Now go back to the quality-settings and see the number of samples.
You'll see they have increased drastically because the thicker and denser the clouds are, the more samples you need to gain/acquire a certain detail/quality-level.

Therefore in general people should not mention samples when referring to clouds, but use detail because that really determines what one can expect.

Cheers,
Martin

[Oshyan]

The haze value may help. I think the default value is 1. Try 2. Also use raytraced shadows in the atmosphere and clouds. This will increase the render time. Sometimes the atmosphere quality samples have to be set Very high. 256 may be enough.

There's no good reason to use raytraced shadows in atmosphere and clouds here, it will only increase render time a great deal more. Is there a particular reason you recommended it?

- Oshyan

[DVA99]

Well I did ticked all boxes for Ray traced shadows the first try but the rendering time increased by 10.
Then I saw a notice in TG2 that using ray traced shadows is only necessary if the terrain cast shadows on the clouds.

So I unticked all the boxes for raytraced shadows. In fact, I decreased almost all quality for the clouds except for the Atmosphere, which I increased to 128.

Render time about 10 minutes which is nothing compared to the earlier tries and the result was good.

But I still think I need to buy the TG2 since I need bigger resolution and probably higher AA.

Cheers

[Henry Blewer]

I have had better atmosphere rays using raytraced shadows, with less atmosphere detail. But the render time increase makes the option extreme.

[Oshyan]

Have you actually tried before/after comparisons? Because the only thing that option *should* do is give you rays *from* terrain into clouds and/or atmosphere. In some cases that would result in "better rays", but if you're talking about a scene with rays coming down from the sky, through the clouds, it should have no effect, and I rather suspect that without a controlled test, it may just be an assumption based on misunderstanding of how that feature works. I'd be interested to see a directly comparable side-by-side test demonstrating the difference, if you can reproduce it.

- Oshyan

[Henry Blewer]

It was rays coming through gaps in the terrain. I abandoned the project, I could not get the fill lighting right.