Celestia Forums

Does anyone here make their own global cloudmaps from scratch for earth-like planets? Is it even possible to do (they are quite complex things, since you have to worry about transparency)? Or do you usually just recycle an cloudmap from earth?

If you do custom build them, can you share any tips for how to do it? Thanks.

Evil Dr Ganymede wrote:Does anyone here make their own global cloudmaps from scratch for earth-like planets? Is it even possible to do (they are quite complex things, since you have to worry about transparency)? Or do you usually just recycle an cloudmap from earth?

If you do custom build them, can you share any tips for how to do it? Thanks.

Certainly.

2 1/2 years ago I did my 2k earth-clouds that have been used by thousands and they are still used by me at least.
I still think they are the best

I did Mars clouds and moving Jupiter cloud belts, I did Titan's haze with just a little bit of transparency...

There is nothing particularly complex involved:

1) Clouds have to be done in a format that supports an Alpha channel (Transparency!). This is a grayscale texture with white corresponding to transparency 0 and black to 100% transparency.

Popular possible cloud texture formats are PNG or DXT3,...
JPEG or DXT1 do NOT work!

2) To get started one may simply use standard cloud generation macros in GIMP or Photoshop, to generate some appropriate grayscale patterns for the Alpha channel.

One click in GIMP (Filters->Render->Clouds->Solid Noise...) would e.g. generate this texture, which could serve as a first go for practicing with an alpha channel.

The desired amount of transparency can be easily adjusted by means of changing Brightness/Contrast



3) One then composes from
--- a uniformely white or gray texture (to be associated with the R,G,B channels each) and
--- that alpha channel texture (A)

a R-G-B-A texture, again using the standard composition command in GIMP (Filters->Colors->Compose...) or Photoshop.

Save it as a PNG texture.
That's it.

There are many variations of this trivial 'starter' kit. Bumpmapping of the clouds is one issue to render them more 3d like. Then it's always a good idea to add some Gaussian Blur to make the clouds more fluffy...

Finally, one may use the R,G,B channels to overlay some base color like blueish, yellowinsh or anything else.

Hi, Evil Dr Ganymede,

Fidger,

This is ok for a cloudmap quite uniform, but doing a realistic Earth cloud map from nothing is very hard (well I think so)...

Personnaly I have done some test, combinating clouds map with your technique (or similar)(also lunarcell can do a not so bad basis) and originals clouds from those on ML, but with LOT of work.
One of the important thing is that (for a earth like planet) the png should have only white to transparent imformation... I have found some maps with greyscale, or blue color in the gradient parts that are not very good once in celestia (due to a wrong way when separated from background)...

The use of Alpha channel/mask is crucial, so are lot of layers, playing with transparency.

If someone has found a performant realistic cloud generator I'm also interested.

Bye

ElChristou wrote:Hi, Evil Dr Ganymede,

Fidger,

This is ok for a cloudmap quite uniform, but doing a realistic Earth cloud map from nothing is very hard (well I think so)...

Personnaly I have done some test, combinating clouds map with your technique (or similar)(also lunarcell can do a not so bad basis) and originals clouds from those on ML, but with LOT of work.
...
The use of Alpha channel/mask is crucial, so are lot of layers, playing with transparency.

If someone has found a performant realistic cloud generator I'm also interested.

Bye

ElChristou,

of course I am aware of this. But EDG does not like it if things become too complicated at the first round . So I wanted to make it as simple as possible, just trying to illustrate the individual basic steps. If you carefully read my above post, you'll notice that I recommended that simple pattern only for practicing e.g. with alpha channels... Incidentally, both for Mars and Titan the GIMP cloud generator is quite adequate.

EDG was NOT interested in an earth-cloud map in the first place. For earth it is best to copy real cloud formations from satellite photographs into the alpha channel. Everyone who has done earth-clouds KNOWS this, but again I wanted to stay easy at first, notably since he was interested in other planets.

One of the important thing is that (for a earth like planet) the png should have only white to transparent imformation... I have found some maps with greyscale, or blue color in the gradient parts that are not very good once in celestia (due to a wrong way when separated from background)...

Here I disagree strongly. Combining the alpha channel info with RGB color allows /in general/ to add some atmospheric color correction that is otherwise impossible within Celestia.
In particular (symmetrical) north-south light color gradients (in cylindrical maps) can be very useful.

Just believe me here. I got plenty of experience with that stuff. But one has to know precisely how alpha+color act in combination!


Bye Fridger

t00fri wrote:... Here I disagree strongly. Combining the alpha channel info with RGB color allows /in general/ to add some atmospheric color correction that is otherwise impossible within Celestia.
In particular (symmetrical) north-south light color gradients (in cylindrical maps) can be very useful.

Just believe me here. I got plenty of experience with that stuff. But one has to know precisely how alpha+color act in combination!...

Yes your right, but I was talking of some maps with a coarse work with result a strange effect specialy went cloud map is entering the night zone... nothing to see with a well calculated effect

One more time I was talking about earth like cloud maps... sur for Mars and Titan yours maps are pretty cool.

Bye

(I think I don't know your earth cloud map... )

I found an interesting tutorial for making Earth like planets at Solar Voyager - Tutorials http://www.solarvoyager.com/tutorials.asp
If you go down to the tutorial for Land Planet it goes through a very detailed way of making a planet. But if you want to skip the planet parts you can go straight to the section were the clouds are made. Very detailed and labor intensive. I haven't tried this myself as of yet. But you could use the same process on a larger scale. Although I have used a few of his techniques in making my clouds but way before I read his tutorial.
As for me I tend to use the same old 16k cloudmap from BlueMarble but I don't leave it intact. I move things around and use Photoshop to do most of my editing. I always work in grayscale with the black and white textures first. This allows you to add other weather systems from satellite imagery. The key is not to go overboard. When I first started adding storms to Earths cloudmaps the scale of the storms was way off, meaning they were to big in size. It took me a while to learn to keep the scale of things in mind. What looks really good in a flat image can look very wrong when put onto a 3D sphere. Certain areas of the texture get stretched more than others and this can also make the texture look bad. It takes allot of time to make really good clouds. Unfortunately we just do not have enough large intact cloudmaps for there to be any real variance in them. Working with the same cloudmap starts to get boring. Let?€™s face it, you can only move the same clouds around so much or add a few things here and there. For me after a while they all start to look the same no matter how different they actually are.
As for Fridger?€™s 2k clouds, I used them for the longest time as a base for my own clouds. At the 2k level they are excellent. But Celestia has moved forward in texture size and the 2k cloudmap is just a little long in the tooth as one might say. It is great for a lower end system but allot of us are working with what a few years ago would be considered super computers. Another issue that I have with Fridger?€™s cloudmap is the blue underlying coloring. It looks great at first but as one starts to look closer at the surface you can see that the cloudmap is coloring things it shouldn?€™t, namely snow and ice. They all take on a very blue hue. That is the main reason I stopped using his 2k cloudmap as a base. Now of course this means my clouds are straight out grayscale which is true. But I have learned a few tricks along the way. I am in the process of writing up an in depth tutorial on cloudmap making. It will be hopefully posted in a few days. And I must say that if it were not for Fridger's and few others help a few years ago I would not even be were I am today. A big hats off to you guys.

Don. Edwards

Don. Edwards wrote:...I am in the process of writing up an in depth tutorial on cloudmap making. It will be hopefully posted in a few days...

Very good news, I will look at it with great interest.
(Also those tutorials on the page you gave are quit good )

Bye

How many cloud maps can you run for a single planet?
Reason i ask is because a set of addons that i am slowly working on is set in Larry Niven's Known Space.
The planet Plateau is basically a Venus like planet with a plateau that sticks above the poisonous cluds...
I wanted to render moving clouds at the lower level and earthlike clouds at the higher level.
can this be done?

Unfortunately, celestia supports only ONE cloud layer, so what you're suggesting is impossible for the time being.

well, hell.... there goes that.....
hm maybe i can try something else.

Mount lookithat would be a good candidate to be made as a Mesh; a mountain similar to the 3ds meshes of Olympus Mons by Jestr...

you could even put a transparent layer in the mesh over the top, lightly coloured by a white and blue cirrus like pattern;
not ideal, but it might be possible to make the skies over Plateau look reasonably Earth-like...
I would try it myself but my computer is misbehaving.

PlutonianEmpire wrote:Unfortunately, celestia supports only ONE cloud layer, so what you're suggesting is impossible for the time being.

That's not so clear . Officially you are right, of course. But there is a trick that has been exploited e.g. by Runar in his great Sun texture:

You may create a 3ds placeholder mesh to which another layer of clouds or anything else may be attached. That mesh has to be located appropriately.

I played quite a bit with this idea in the context of modelling a better Titan atmosphere. I also know that Runar is following similar aims...

Bye Fridger

t00fri wrote:...I played quite a bit with this idea in the context of modelling a better Titan atmosphere. I also know that Runar is following similar aims...

This has been succesfull? do exist a post with an url to download your (old) test? (I haven't found)... I'm quite curious...

ElChristou wrote:

t00fri wrote:...I played quite a bit with this idea in the context of modelling a better Titan atmosphere. I also know that Runar is following similar aims...

This has been succesfull? do exist a post with an url to download your (old) test? (I haven't found)... I'm quite curious...

I did'nt quite understand. Sorry.

What did you look for? what kind of test? I did hundreds of (old) "tests" during the last 3 years

Indeed, Runar's trick works, in case you mean that.

Bye Fridger

t00fri wrote:

ElChristou wrote:

t00fri wrote:...I played quite a bit with this idea in the context of modelling a better Titan atmosphere. I also know that Runar is following similar aims...

This has been succesfull? do exist a post with an url to download your (old) test? (I haven't found)... I'm quite curious...

I did'nt quite understand. Sorry.

What did you look for? what kind of test? I did hundreds of (old) "tests" during the last 3 years

Indeed, Runar's trick works, in case you mean that.

Bye Fridger

Oops sorry!!
As you say you had played with this (in the past obiously) the question was (is) if you have developped multi clouds textures to use with the Runar's trick... and if they are available somewhere to download...
Note that if I ask you that it's not because I'm lazy to do some clouds textures, but as I use your complet package for Titan, I prefer a 100% original Fridger's work...

ElChristou wrote:

t00fri wrote:

ElChristou wrote:

t00fri wrote:...I played quite a bit with this idea in the context of modelling a better Titan atmosphere. I also know that Runar is following similar aims...

This has been succesfull? do exist a post with an url to download your (old) test? (I haven't found)... I'm quite curious...

I did'nt quite understand. Sorry.

What did you look for? what kind of test? I did hundreds of (old) "tests" during the last 3 years

Indeed, Runar's trick works, in case you mean that.

Bye Fridger

Oops sorry!!
As you say you had played with this (in the past obiously) the question was (is) if you have developped multi clouds textures to use with the Runar's trick... and if they are available somewhere to download...
Note that if I ask you that it's not because I'm lazy to do some clouds textures, but as I use your complet package for Titan, I prefer a 100% original Fridger's work...

NO, I did not release any respective stuff. I tend to release only a small proportion of the things I try. It was actually quite recently that I played extensively with Runar's trick.

It seems to work well, but I have little experience with making /new/ custom 3ds meshes. I just never got involved much with that stuff, since under Linux good 3ds software is rare. Blender is not my "destiny"

Bye Fridger

t00fri wrote:...It seems to work well, but I have little experience with making /new/ custom 3ds meshes. I just never got involved much with that stuff, since under Linux good 3ds software is rare. Blender is not my "destiny"...

If you need 3d stuff, just ask...

Thanks for the links and tutorials folks, I'll try out what Fridger suggested.

I was actually thinking about earth-like planets... I was ultimately wondering how easy it would be to come up with cloud maps that had the cloud bands and cyclones etc like Earth does... but I do think it's better to start simple and then progress onto the more complicated stuff .

Evil Dr Ganymede wrote:Thanks for the links and tutorials folks, I'll try out what Fridger suggested.

I was actually thinking about earth-like planets... I was ultimately wondering how easy it would be to come up with cloud maps that had the cloud bands and cyclones etc like Earth does... but I do think it's better to start simple and then progress onto the more complicated stuff .

Let us know your progress on this... If I find a minute I will do a new 4k earth like cloud map.

Bye

ElChristou wrote:

Evil Dr Ganymede wrote:Thanks for the links and tutorials folks, I'll try out what Fridger suggested.

I was actually thinking about earth-like planets... I was ultimately wondering how easy it would be to come up with cloud maps that had the cloud bands and cyclones etc like Earth does... but I do think it's better to start simple and then progress onto the more complicated stuff .

Let us know your progress on this... If I find a minute I will do a new 4k earth like cloud map.

Bye

I am sure you know that 4k clouds DON't move...2k is the maximum for having CloudSpeed <>0

Bye Fridger