Discussion Solar system generator planet classes?

Artlav

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Goal: to make a believable-looking solar system out of one number.
Means: fractally generated landscapes and textures assigned based on accretion-model defined planet class.

Sounds easy, but the key word is believable-looking, so the question is, does these two planets look believable for their description?
If no, what changes do you propose?

Desert class planet.
Thin CO2 air, rare water ice, 34C average temperature, 0.61g gravity.

Overview:
oru-ss-090220-1.jpg

Close-up:
oru-ss-090220-4.jpg



Iceball class moon.
No air, water ice, -121C average temperature, 0.17g gravity

Overview:
oru-ss-090220-2.jpg

Close-up:
oru-ss-090220-3.jpg
 

willy88

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Hmm, I think that the iceball-class planet would look something a bit more like Europa, personally.
 

Scrooge McDuck

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I think there is another important thing.
The angular velocity of a planet has probably a big effect on how it will look. Rotation is not in your given numbers, or does your generator create random numbers for this too?
When it always faces one side to the star, there will probably be huge differences in the sunny/dark sides. When it rotates faster, there will probably be typical polar regions and warmer regions near equator.
 

Hielor

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Wow, that's awesome.

They do look rather believable for the most part, but perhaps a little too "noisy" from the orbital (not close-up) view--that is, it seems almost too random. For example, from this image of mars: http://blog.wired.com/wiredscience/images/2007/12/18/mars.jpg

You can see that there are lots of places where it's a single (or close to a single) uniform color for large parts, and there's a great deal of color variation. The ones you have there only look to have 2-3 colors, and the placement seems almost entirely random, rather pixelated if that makes sense.

For some planets that could make sense (ie, it doesn't look bad at all for the ice planet), but for the desert one it looks kind of sploltchy.

Oh I think I may know what I mean...on a planet with an atmosphere, there will be erosion which over millions of years will smooth out differences and result in large areas with only subtle variations of color, rather than speckles of a color throughout.

Does that make sense?

It still looks really good though, and the close-up looks fantastic. Is that in Orbiter? I really like the atmospheric haze effect, although it seems maybe a little too thick for a planet with a thin atmosphere.
 

McWgogs

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Yes, they seem to random, even the ice world one. Needs big features.
And craters.

Still, it looks great, i would love to explore these.
 

Linguofreak

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Goal: to make a believable-looking solar system out of one number.
Means: fractally generated landscapes and textures assigned based on accretion-model defined planet class.

Sounds easy, but the key word is believable-looking, so the question is, does these two planets look believable for their description?
If no, what changes do you propose?

Desert class planet.
Thin CO2 air, rare water ice, 34C average temperature, 0.61g gravity.

As far as visual realism: Such a planet will not necessarily be a clone of Mars, so it might be good to have some different colors that a desert planet with thin CO2 air can have. That said, it looks alot better than anything I could have programmed or hand-drawn.

As far as other types of realism: I'm not certain that a planet with 0.61g gravity would necessarily have a thin atmosphere. Unless it's significantly denser than Mars, its escape velocity will be alot higher, and that will mean the atmosphere doesn't escape as quickly. Also, the bigger and more massive a planet is, the more internal heat it has, and thus the longer it stays tectonically active. The longer it stays tectonically active, the longer volcanoes continue to replenish the atmosphere. It may not be nearly as thick as Earth's atmosphere, but it will probably be much thicker than Mars'
 

Namahage

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I think they look great. Any plans for fissures in ice? How about volcanos or gullies?
 
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Artlav

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Hmm, I think that the iceball-class planet would look something a bit more like Europa, personally.
Well, Europa function is kind of hard to put together.
But i got the point.
oru-ss-090221-2.jpg

What could be present in the ice to make it look like that, btw (except for pink paint)?

Rotation is not in your given numbers, or does your generator create random numbers for this too?
Pretty much either a random number or a near-tidal lock.
For the Desert one - 47 hours, 60Gm orbit around K6 V 0.6*sun star.

You can see that there are lots of places where it's a single (or close to a single) uniform color for large parts, and there's a great deal of color variation. The ones you have there only look to have 2-3 colors, and the placement seems almost entirely random, rather pixelated if that makes sense.
Well, how to obtain a more natural set of colors? For the desert one there is a mix of 12 defined colors in 4 groups of shades, plus their intermixes.

Is that in Orbiter?
OGLAClient & SpaceWay, closely compatible.

Yes, they seem to random, even the ice world one. Needs big features.
Does it need a sharpening, recoloring, or maybe just blurring?
What about that?
oru-ss-090221-1.jpg


As far as visual realism: Such a planet will not necessarily be a clone of Mars, so it might be good to have some different colors that a desert planet with thin CO2 air can have.
Well, the colors are the thin point. How do i figure which colors are good? Just make it look good for some definition?

What about:
oru-ss-090221-3.jpg

Or maybe:
oru-ss-090221-4.jpg

And why not:
oru-ss-090221-5.jpg


That is the big question - just how do you paint planets?

Anyone seen a "planet making for dummies" book around?

As far as other types of realism: I'm not certain that a planet with 0.61g gravity would necessarily have a thin atmosphere.
It's the size of Mars, but somewhat denser, with 0.02 atm of air. Molecular limit calculated at 20, no moons, no significant magnetic field.
Makes sense?
 

T.Neo

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What could be present in the ice to make it look like that, btw (except for pink paint)?

Some sort of alien liform perhaps? Pink algae?

And why not:
oru-ss-090221-5.jpg

Purple planet? :rofl:

EDIT:
Anyone seen a "planet making for dummies" book around?

That question has motivated me to write one...
 

McWgogs

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Maybe i used a wrong word. Not too random. They are too noisy, as it was already said. The features are very alike, repetitive, you can see they're based on a simple function. Still it looks better than Noctis. :p In other word, they should be more random. So the planets are more unique, and you can't know what's on the other side of a planet until you look there.

Also, don't base the appearance of a planet on the planet class (ice ball, thin atmosphere ect) Base the class on the appearance of the planet!


As for colors, most asteroids, moons are near gray-pale orange.
So the more saturated colors of the rocks are, the less likely they should be.
Planets with atmosphere should be more color saturated, but not too much.
Gas giants can be even more saturated, but not too much. Planets aren't that colorful.

The class of the main star/stars should of course have an impact on colors
 
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markp

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Both planets look good in the first post. I think the Mars-like one needs clouds. Also the dark splotches could perhaps be more splotchy i.e. at the moment it looks like there is some global process working in an east west direction on the planet...can't think what that would be.

The ice planet looks nice but as already mentioned it could be described differently.
 

Linguofreak

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That is the big question - just how do you paint planets?

Well, unless there's iron to oxidize on the surface (as in Mars' case), I'd expect rock-type colors, brown or grey. If the atmosphere is dense enough and the temperature's right, you'll have some surface water, which will be blue. (With the pressure's and temperatures you have for your desert planet, I'd almost expect to see more water than ice, at least on the day side. 0.02 atmospheres is above the triple point pressure of water, and a 34C average temperature might mean that few places on the day side are ever below the freezing point).

The big thing is figuring out the materials that make up your surface (rock, ice, whatever), and how they will react chemically with the chemicals in your atmosphere and any rain. This will determine the colors you get.

Anyone seen a "planet making for dummies" book around?

Someone recommended World Building, by Stephen Gillett, to me a while ago, but I haven't bought it yet...

It's the size of Mars, but somewhat denser, with 0.02 atm of air. Molecular limit calculated at 20, no moons, no significant magnetic field.
Makes sense?

Well, the problem is with it being the size of Mars and having a 0.61 g surface gravity. That would require a density of around 6300 kg/m^3, which for a planet of that size would require a huge iron core, taking up more of the planet than even Mercury's core. At that point you might well have a significant magnetic field, although that is not the primary thing working against atmospheric loss. With about 1.6 times the mass and the same surface area, it will start off hotter inside and cool more slowly than Mars, which will mean more gasses released by vulcanism over a longer period, which will mean a somewhat thicker atmosphere.

Then again, with so much iron in the core, I wouldn't be so surprised to see iron on the surface of this particular planet, so it might just have a Mars-like reddish tint...

A more reasonable density for that surface gravity might be somewhere in the 4000's of kg/m^3 (lower 4000's in an iron poor system, higher 4000's or maybe even low 5000's in an iron rich system, or if the planet has had alot of its mantle blown away by some impact. I'd say 4500 is a fairly reasonable density to expect, though the average might be a bit higher or lower). Assuming a density of 4500, you get a radius of about 4750 km, and a mass of about 1/3 Earth's. Escape velocity is then about 7500 m/s. The higher escape velocity should work against atmospheric escape.
 

willy88

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If the atmosphere is dense enough and the temperature's right, you'll have some surface water, which will be blue.

Wouldn't the colour of the oceans (if they're water) depend on the colour of the atmosphere?
 

Artlav

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Purple planet?
Well, there are some in Spore.

The features are very alike, repetitive, you can see they're based on a simple function.
...
So the planets are more unique, and you can't know what's on the other side of a planet until you look there.
What about the latter planets with large features?
Do you mean feature-unique or conceptually unique?

Here is the look with somewhat more varied colors and less random, large features:
oru-ss-090222-1.jpg

Same, with clouds:
oru-ss-090222-2.jpg

Other side with different clouds:
oru-ss-090222-3.jpg


Also, don't base the appearance of a planet on the planet class (ice ball, thin atmosphere ect) Base the class on the appearance of the planet!
Sounds easy, but how do you do that? Make a set of planets, then arrange them around into a solar system, instead of making a solar system and painting planets according to where they fell to?
Sounds like it will be less realistic, or just as random anyway.


Someone recommended World Building, by Stephen Gillett, to me a while ago, but I haven't bought it yet...
Unfortunately, neither buyable nor downloadable out here.
 

Linguofreak

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Here is the look with somewhat more varied colors and less random, large features:
oru-ss-090222-1.jpg

Same, with clouds:
oru-ss-090222-2.jpg

Other side with different clouds:
oru-ss-090222-3.jpg

Niiiiiice...

At this point the planet itself looks quite convincing to the eye. Some of the surface features look a bit weird as far as scientific realism (namely the long darker colored strips on either side of the brownish "mountain range," and the presense of ice caps on a planet with a 34 degree average temperature), but the visual realism is excellent.
 

Hielor

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I really like the last few, they're looking really good. The one thing I'm not sure about are the streaks that flow around the planet. They could be a reasonable thing, but you'd want to make sure that not all planets have them. Could we see another few planets of the same type?
 

McWgogs

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making a solar system and painting planets according to where they fell to

Pretty much what i meant. :p Generate the characteristics of a planet based of solar system formation theories, and base the planet class on what comes up. There should be a lot of variety so you can't really tell what class a planet is just by looking on it. Kinda like in spore where just by adjusting the temperature, you can smoothly turn a ice ball i to a lava planet.
 

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As far as other types of realism: I'm not certain that a planet with 0.61g gravity would necessarily have a thin atmosphere. Unless it's significantly denser than Mars, its escape velocity will be alot higher, and that will mean the atmosphere doesn't escape as quickly. Also, the bigger and more massive a planet is, the more internal heat it has, and thus the longer it stays tectonically active. The longer it stays tectonically active, the longer volcanoes continue to replenish the atmosphere. It may not be nearly as thick as Earth's atmosphere, but it will probably be much thicker than Mars'

A planetary magnetic field has an important effect too. A planetary magnetic field, such as Earth's, deflects solar wind particles around the atmosphere. Mars does not have a planetary magnetic field. One theory holds that, over time, the solar wind impacted directly on Mars atmosphere and blew it away.
 

T.Neo

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A crater generator would be a good addition, Artlav, to scatter craters over the surface.

Lower areas tend to get filled in with lava and thus are younger and have less craters.

And remember what causes topography- impacts, volcanic domes, rifts, etc.

P.S. Do you know about Sudarsky Planet Types? Very useful in determining the appearance of gaseous planets.

EDIT:
Well, there are some in Spore.

I guess that could happen if the vegetation was purple, but I think I read somewhere that purple vegetation is unlikely.
 
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