Clouds hugging the terrain?

Started by JimB, January 06, 2007, 07:41:26 PM

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JimB

Is there any feasible way to make a cloud layer follow the shape of a terrain, instead of being in a single plane of altitude? I thought it could be useful for ground-hugging mist, and getting cloud to rise over mountains, etc.
Some bits and bobs
The Galileo Fallacy, 'Argumentum ad Galileus':
"They laughed at Galileo. They're laughing at me. Therefore I am the next Galileo."

Nope. Galileo was right for the simpler reason that he was right.

rcallicotte

If you mean can you change the height of the clouds, yes.  It's in the clouds properties.
So this is Disney World.  Can we live here?

Njen

No, what I think he means is to get the clouds to follow to surface, say up a mountain and stay at a constant distance from the terrain at all times.

I have been trying a few ideas to get this working...nothing successful so far :(

JimB

#3
Quote from: njen on January 07, 2007, 10:36:34 AMwhat I think he means is to get the clouds to follow to surface, say up a mountain and stay at a constant distance from the terrain at all times.

That's the one. Like this:
http://www.poolewehotel.co.uk/photo.asp?id=905
And this:
http://www.capetownskies.com/9255/17_fog_rumpb.jpg

QuoteI have been trying a few ideas to get this working...nothing successful so far :(

Me neither. Using a low res version of the Compute Terrain to offset the Y value of the clouds locally would be sweet, but I can't see that happening for a long time.
Some bits and bobs
The Galileo Fallacy, 'Argumentum ad Galileus':
"They laughed at Galileo. They're laughing at me. Therefore I am the next Galileo."

Nope. Galileo was right for the simpler reason that he was right.

Njen

I was trying some sort of 3D mask using a larger version of the same terrain, but no luck there :(

rcallicotte

Cooool.

Quote from: JimB on January 07, 2007, 10:49:26 AM
Quote from: njen on January 07, 2007, 10:36:34 AMwhat I think he means is to get the clouds to follow to surface, say up a mountain and stay at a constant distance from the terrain at all times.

That's the one. Like this:
http://www.poolewehotel.co.uk/photo.asp?id=905
And this:
http://www.capetownskies.com/9255/17_fog_rumpb.jpg

QuoteI have been trying a few ideas to get this working...nothing successful so far :(

Me neither. Using a low res version of the Compute Terrain to offset the Y value of the clouds locally would be sweet, but I can't see that happening for a long time.
So this is Disney World.  Can we live here?

Oshyan

This may be possible through the Function nodes or through some other cunning trickery. You'd basically want to displace the cloud density fractal by the terrain shape. It seems at least plausible...

- Oshyan

JimB

I had a go, but the result was a bit of a car wreck. I *think* the clouds were following the terrain, using a smoothed duplicate of the heightfield shader, which plugged into a Get Altitude function, that plugged into a Displacement, that plugged into the cloud Fractal node. The atmosphere had to be sacrificed - no way could I get the tree to work with the atmosphere affecting the terrain.

Then TG crashed.  >:(
Some bits and bobs
The Galileo Fallacy, 'Argumentum ad Galileus':
"They laughed at Galileo. They're laughing at me. Therefore I am the next Galileo."

Nope. Galileo was right for the simpler reason that he was right.

jo

Hi,

A while back I tried making a tornado using function nodes to modify a cloud layer. I didn't get very far. I have a suspicion that trying to manipulate cloud layers in this way isn't possible just yet. I might have another go if I can find some spare time.

Regards,

Jo