Cloud Hole Puncher

[TheBadger]

Hello.

I have been trying to use Dune's "hole puncher" (Found here: http://www.planetside.co.uk/forums/index.php?topic=14665.msg143554#msg143554 )
on FrankB's overcast clouds (found here: http://store.nwdanet.com/terragen2store/6-terragen-2-presets/7-atmosphere-a-clouds/72-cloudy-day-by-frankb.html )

I would like to add the punch to create an additional light beam to the default clouds. So I can make a point of interest in an image Im doing really pop.

But I am having a good bit of difficulty getting this to work. The clouds in franks file are bit more complex than the sample clouds in Dune's experiment. Still I think it can work?

Can anyone tell me how to do this to the default clouds in frank's preset?

Thank you.

[Dune]

You could also punch a hole by using a mask (white dot on black) with a camera pointing at the sun from where the cloud is that you want to lighten, and use that to inversely blend the cloud layer(s) above it.

[Tangled-Universe]

...with a camera pointing at the sun from where the cloud is that you want to lighten...

Ehhrrr....huh??? After reading a couple of times I have no idea what you mean here Ulco.


Michael,

The simplest way to get started is to replace the cloud-fractals completely by a distribution shader.
Then use Ulco's hole puncher file to find the sweet spot you're looking for.
If you have found it then remove the distribution shader and reconnect Frank's fractals to the cloud.
Use the hole puncher's output as blendshader for Frank's clouds.

Another way, though not so very easy, is to use a distance shader.
By default the distance shader creates a 10km wide black soft dot at the position where the camera is positioned.
Given that you use spherical projection.
With a bit of basic math and a bit of guesswork you can position the camera inside the cloudlayer to create a hole.
To make the light beam more visible you can disable GI temporarily.

[TheBadger]

Hi guys, thanks for the words.

I got it working:
[attachimg=1]

Adding the distribution node was key, thanks for that. But the set up needs to be a little different than suggested.

For anyone who might want to know

1) The new distribution node is plugged into the the density port of the cloud node
2) the original density fractal for the cloud is plugged into the blending shader of the new distribute node.
3) Dune's "punch" then should be plugged into the *child* input of the new distribution node.
In the case of FrankB's clouds it is only necessary to plug the punch into the main cloud node "High Alt. Cumulus". But you can plug the punch into as many cloud layers as you like with this set up.

Other ways of plugging the punch into frankB's clouds may have an effect, but the effect was either minimal, or negatively affected the appearance of Frank's clouds.

Anyway, it is best to set the Simple Shape Shader to a very large size when starting out.

Thanks again fellas.