Question about clouds

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PlasticMan
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Question about clouds

Post #1by PlasticMan » 15.11.2006, 03:43

Kinda new to this, a couple questions.

Is there a command to make clouds turn the oposite direction?

Is it possible to have 2 cloud layers?

Could someone give me an example of how it would look in the ssc?

Ive been going through all the 9, er uh, 8 planets installing addons for each one, putting my own little modifications here and there. Im curently on jupiter and thought id try to give the couds a bit of life. Im having a blast with this!!

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PlasticMan
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Post #2by PlasticMan » 15.11.2006, 22:35

Anyone?

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selden
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Post #3by selden » 15.11.2006, 22:42

You should be able to make clouds go backward by setting CloudSpeed to a negative value.

Celestia does not yet have the ability to display more than one cloud layer around the same SSC object. One workaround is to define more than one SSC object with the same orbital parameters, each with its own cloud layer. Celestia should be able to draw them individually. My personal experience with this isn't all that great. I see nasty visual artifacts around the edge of the sphere.
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Post #4by Chuft-Captain » 16.11.2006, 07:26

selden wrote:One workaround is to define more than one SSC object with the same orbital parameters, each with its own cloud layer. Celestia should be able to draw them individually. My personal experience with this isn't all that great. I see nasty visual artifacts around the edge of the sphere.

My guess is that these nasty artifacts are caused by Z-fighting. Try giving the objects slightly different radii. I don't know if that will fix it, but worth a try IMO.
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avpruler
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Post #5by avpruler » 16.11.2006, 14:04

BOUT TIME! finaly someone who wants better clouds!
for jupiter you should making first a 2-d layer of the jupiter texture then you go below it and there are 3d clouds.!

just my oppinion.
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PlasticMan
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Post #6by PlasticMan » 16.11.2006, 16:32

What I am trying to do is is make 2 sets of clouds for jupiter, one turning one way, the other turning the oposite direction to give it kind of a stormy effect. I know its probably not realistic or accurate, but hey, it would look nice! Plus im having alot of fun learning how to do this stuff! My real goal is to eventually make some fictional gas giants, maybee to go in a fictional solar system, im just practicing on Jupiter.

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Post #7by rra » 16.11.2006, 17:42

selden, plasticman ,

I tried reversing the cloud's direction by settings its speed to -7,
but the rotation always seems to be to the same direction.
Also I get a strange artifact when setting the speed to negative values:
(I found it on2 windows PC's).

***************************

I have some trouble with my image host,
can show the artifact later I hope,
that is , if someone is interested.

****************************

Ren?©

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selden
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Post #8by selden » 16.11.2006, 22:50

I just now used this ssc and it worked fine for me
Modify "Earth" "Sol" {Atmosphere { CloudSpeed -100 }}

this was with the cvs version of celestia.
I don't have time to test it with 141 this instant.
Selden

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Post #9by Chuft-Captain » 16.11.2006, 22:59

Selden, what was the verdict on the nasty artifacts? Did varying the radii solve this, or did you not have time to try?
"Is a planetary surface the right place for an expanding technological civilization?"
-- Gerard K. O'Neill (1969)

CATALOG SYNTAX HIGHLIGHTING TOOLS LAGRANGE POINTS

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selden
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Post #10by selden » 17.11.2006, 02:15

I was seeing the artifacts when using different sized planets. But now I can't reproduce it. *sigh*
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Post #11by selden » 17.11.2006, 02:29

The ssc below does produce different (wrong) results in v1.4.1final. Only one cloud layer is visible most of the time, but I can see bright flashes that seem to be the other layer.

However, it seems to do the right things when using Celestia built from cvs. The Earth looks really weird with one layer of clouds flowing from east to west while the planet and the other cloud layer are turning from west to east.

Chris rewrote the depth sorting routines in v1.5 to work better with cloud layers, so that's something for people to look forward to :-)

Code: Select all

Modify "Earth" "Sol" { Atmosphere { CloudHeight 200 CloudSpeed -1000 } }

"Earth2" "Sol"  {
   Radius 6200
   Atmosphere {
      CloudHeight 200
      CloudSpeed  200
      CloudMap "earth-clouds.*"
   }
   CustomOrbit "vsop87-earth"
   RotationPeriod   23.9344694 # 23.93419
   Obliquity        -23.45
}
Selden

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PlasticMan
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Post #12by PlasticMan » 17.11.2006, 22:25

selden wrote: My personal experience with this isn't all that great. I see nasty visual artifacts around the edge of the sphere.



Is this what you mean?

http://i143.photobucket.com/albums/r142 ... titled.jpg

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selden
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Post #13by selden » 17.11.2006, 22:30

What I was seeing was irregular jaggies around the outer edges of the planet when using two levels of Celestia's default Earth clouds. As I wrote, though, I couldn't make it happen again when I recreated the ssc file (I'd accidentally deleted the one I had been using).

Which version of Celestia are you using?
Which render path are you using?
Selden

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PlasticMan
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Post #14by PlasticMan » 17.11.2006, 23:06

Im running 1.4.1. Not sure on render path, thats a new one! (still learning)

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Post #15by selden » 17.11.2006, 23:51

Type a ctrl-V several times
It will step through the Render paths that Celestia believes that it can use on your system.

The most elaborate eye candy is shown if your system can display "Render path OpenGL 2.0"
Selden


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