Need some help on how to improve my clouds.

[Felix]

Hi there !
This is my first post on the board, and id like to start of with that i think that TG2 is a wonderfull piece of software, and the artist using it are very talented!
Ive worked with the first Terragen, and thought that it was a very usefull program. Now that im in need for a skybox for my Half-Life 2 mod, i dusted of my TG2 demo.
What im trying to achieve is a skybox (6 images; front, back, left, right, top and down that make up the sky in videogames) set in a desert with big (huge really) cumulus clouds.

Currently ive been playing around and managed to figure out how the basics work in TG2. I made this:
(I know, it still needs alot of work)




This is more in the direction of what im trying to make:



What id really like to know is how i can get rid of:
-clouds not "staying together", there are too many lose pieces of cloud.
-clouds having abstract forms. i think this is quality related (?)
-the shadows of the clouds miss a form of "ambient occlusion" so that the shapes and forms are still visible in "unlit" places.

Any feedback, suggestions, tips more then welcome ! : )
Thanks,

-Felix

[rcallicotte]

Here might be some examples you could learn from - http://forums.planetside.co.uk/index.php?topic=3691.0

[Felix]

thank you, really helpfull! : D

-Felix

[EBAndrew]

Not sure if this GI bug has been fixed yet (haven't made a skybox with TG2 for a bit now) but you're going to need to disable Global Illumination for your renders. Otherwise you'll find that the lighting doesn't match up between the six images.

If it still hasn't, there's a couple GI substitutes around here on the forums... Oshyan's got a good one http://forums.planetside.co.uk/index.php?topic=580.0 and BigBen's got one as well http://forums.planetside.co.uk/index.php?topic=1921.msg18762#msg18762.

Happy Skyboxing! (Fight it good!)

[moodflow]

The photo you posted is an example of clouds most of us are still trying to master. 

We've made some amazing progress so far, but I personally haven't seen any TG2 renders featuring clouds that look like that just yet.  Some close, but still work to do.

For something like that, I believe it will require some "deliberate" work, and likely won't be created in a few minutes with standard nodes. 

[Oshyan]

I think you'll find that everyone in the entire CG industry struggles with creating realistic clouds of that type. The only examples I've seen that are as convincing (or in rare cases more so) than TG2's are from dedicated volumetrics systems like Digital Domain's "Storm" or Lightwave's "Hypervoxels".

That being said it's also challenging to get the best results from TG2. Only a few have been able to create good examples. There are numerous threads around the forums discussing possible techniques; some have even shared example files to learn from (check the File Sharing area).

In regards to your image as it is now, I would recommend reducing the Smallest Scale size in the Density Fractal (it should be at 10 or so and is measured in meters). It might also be that your Roughness is too low. To get rid of the small, separate clouds, you can experiment with the values of Bouyancy From Variation in the Cloud density shader Tweak Noise tab and the Coverage Gamma in the Cloud shader node itself.

- Oshyan

[Seth]

The photo you posted is an example of clouds most of us are still trying to master. 

We've made some amazing progress so far, but I personally haven't seen any TG2 renders featuring clouds that look like that just yet.  Some close, but still work to do.

For something like that, I believe it will require some "deliberate" work, and likely won't be created in a few minutes with standard nodes. 

http://lucbianco.free.fr/2bgal/img/T2_2008/TGD838.jpg
http://lucbianco.free.fr/2bgal/img/T2_2007/TGD823.jpg
http://lucbianco.free.fr/2bgal/img/T2_2007/TGD822.jpg

close enough to me

[rcallicotte]

This could help.  Learn from examples here - http://forums.planetside.co.uk/index.php?topic=3691.0

[moodflow]

The photo you posted is an example of clouds most of us are still trying to master. 

We've made some amazing progress so far, but I personally haven't seen any TG2 renders featuring clouds that look like that just yet.  Some close, but still work to do.

For something like that, I believe it will require some "deliberate" work, and likely won't be created in a few minutes with standard nodes. 

http://lucbianco.free.fr/2bgal/img/T2_2008/TGD838.jpg
http://lucbianco.free.fr/2bgal/img/T2_2007/TGD823.jpg
http://lucbianco.free.fr/2bgal/img/T2_2007/TGD822.jpg

close enough to me

I agree... these are pretty darn good and are what I first thought of.  However, I still think there is some work to do to get them to look like the photo from the OP.