Celestia Forums

First we'll need a rectangular canvas. 630x50 is OK.
Step 1. Set the background color to black and the foreground color to dark gray. With the airbrush tool, cover the whole image in dots of dark gray. This is also the best time to add colors, but I'll keep it simple and use just shades of gray.

Now you want to fill random patches of the canvas with black, this will create most of the detail in your texture.

Now we are going to define the shape of the rings. Using the rectangular selection tool, select areas of the texture and press Ctrl+I to invert the colors. Repeat until you like how it looks. If you want to erase rings from part of your texture, use the rectangle tool to black out those areas. Likewise, if you want to make sure rings appear in certain areas, use the rectangle tool, but using white this time.

This is the part where we turn our ugly, black and white, blocky, excuse for a texture, into a basic ring texture. Go to Image>Stretch/Skew... and in the Vertical box under Stretch, type 1. Now go into Stretch/Skew and type 500 into the Vertical box under Stretch. Repeat until the texture is 50 pixels tall. We're done with it in Paint now.

Save your ring texture somewhere, then open it in GIMP. First thing we'll do is resize the image to1024x64. While increasing the size does not add detail, it does preserve the detail we already have. Now just go to Colors>Color to Alpha and select black as the color you want to turn transparent. You're done with your ring texture. Save it as your_filename_here.png, and it's ready to use in Celestia.

Thank you.
Never thought about doing it like that.

Tim

Incidentally, there is no need for a ring texture to be more than a couple of pixels high in Celestia.

For example, take a look at saturn-rings.png in ...\textures\lores

CC

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Chuft-Captain wrote:Incidentally, there is no need for a ring texture to be more than a couple of pixels high in Celestia.

I know, it just makes the texture easier to work with.

how would i get a ring texture to go around a star?

i tried to do it but idk. i want it to look like an asteroid belt. but i dont want a real cmod asteroid belt cuz my comp sucks. i just want a nice ring of stuff flying around my fictional star. with planets inside and outside the orbit of the ring.

can anyone help?


i noticed that for saturn the ring distances are in km right?

so i put the "Ring" code in my stc for my star, and drastically increased the distances to fit into a region that is uninhabited by bodies in my system.

roughly 128,347,890,511km to
149,195,741,382km



this is between 3 planets closer to the star and the rest of the planets on the other side of the ring(s)

someone help me out please

Rings only go around planets. You can place a planet at the center of the Sun (SemiMajorAxis 0) and make large rings around that.

However, Celestia's rings are continuous. They aren't made up of lots of tiny objects like you'd expect to see in a dense asteroid belt. You might need to consider creating a 3D model containing many tiny rocks. It'll have better fps than many separate asteroids, but maybe not enough.

selden wrote:Rings only go around planets. You can place a planet at the center of the Sun (SemiMajorAxis 0) and make large rings around that.

However, Celestia's rings are continuous. They aren't made up of lots of tiny objects like you'd expect to see in a dense asteroid belt. You might need to consider creating a 3D model containing many tiny rocks. It'll have better fps than many separate asteroids, but maybe not enough.

right i realize it won't look like a real asteroid belt, but i'm ok with that. my addon is roughly 200mb so on this computer it take a minute to load up. i don't want a butt-load of asteroids i just want what looks like a nice, thin ring of dustiness (if that's a word) around my star. i tried making a planet orbiting Odin with a semimajor of 0. i made it 1km in diameter, i made it have rings and i set the ring distance to what i want, in km. but they didn't show up. is it necessary that the invisible planet have a texture? i tried with texture and without and still no results. could you try it out and see if it works for you?

Unfortunately, I'd forgotten about the illumination. The algorithm that's used to illuminate the rings by the Sun assumes that light comes from the side, not the center.

You're going to have to use several models. They don't have to be of individual rocks, though. In principle a model could be a large fraction of the ring with a surface texture which is a picture of many rocks. A single model of the entire ring can't work, since the illumination algorithm assumes light comes from one side of an object.

There are already LOTS of ring and accretion disk models available on the forum. Why don't you use the search button to find them ?

Few examples :

viewtopic.php?f=6&t=10827&hilit=sprites+ring&start=75

viewtopic.php?f=6&t=16587&hilit=sprites+ring

viewtopic.php?f=6&t=16628&p=127955&hilit=sprites+ring#p127955

Cham wrote:There are already LOTS of ring and accretion disk models available on the forum. Why don't you use the search button to find them ?

thank you i like your suggestions. but i don't think i want to have such a heavy thing in my system. it might make my computer lag out too much. i just want a 2d ring around my star and i can't seem to figure out how to do it.

Have you tried putting in your SSC? That disables shading on planets and their atmospheres. It probably affects rings too. If that doesn't work try using a billboard.

One way to put a ring around a star is to use a flat "billboard" model centered on the star. Its surface texture would be a picture of a circle. Because of how Celestia is designed to illuminate orbiting objects, Emissive true is needed.

See the contents of the "addon" for details.