AstroSynthesis, FT3, and Some Sciency Stuff

[EpicBradley129]

So I've been playing around with the demo versions of AstroSynthesis 3.0 and Fractal Terrains 3, and I have some questions about each of them. For AS3, I'm mainly concerned about whether the program is working properly on my computer, since I've heard that it doesn't work on some computers, and I've been having some weird problems with it which may or may not be serious. For FT3, I have a few questions about specific functions within the program, but mostly I want to figure out what the program is telling me about the physical characteristics of my planet. That last bit is where my questions really become more about climatology and geography and some astrophysics than they are about cartography, so I'm not sure how much you guys will be able to help there. If you can point me to some other forums or resources for the sciency aspects of worldbuilding, that would be great.


AS3:

My basic question here is, how well will this program work on my computer? It seems to work most of the time, but it also crashes quite a bit, although not every time I use the program. Sometimes images don't appear properly, too. The first time I started the program, it showed me a black screen with a cube drawn in dashed, white lines, instead of the spherical grid thing. When I just recently started the program, however, it showed me the spherical grid. The program also has a tendency to show habitable planets as featureless white/grey spheres in the small top left window, and when I expand that window, the planets disappear altogether and are replaced by blackness. However, it has correctly displayed habitable planets at least once before. Do these issues seem like they could be indicative of a major problem, or are they just some graphical glitches?

And then there was the time I tried making a solar system. I started out with just a single star with nothing orbiting it, then added a habitable planet. The program added the planet, complete with earth-like surface conditions, but at a distance of 0 km from the sun. I could change it's distance from the sun and it would appear normally, but this was still very worrying for me because having an earth-like planet inside a star is obviously impossible, yet it still gave me moderate surface temperatures and an earth-like atmosphere. Was this just a one-off problem, or does AS3 not calculate your world details correctly?

If it helps, below is a link that gives the specs for my computer.

http://www.samsung.com/us/computer/p...5E-S01UB-specs

And here are the requirements for AS3, as given on NBOS website. I can't really tell if my computer meets these requirements, so if someone who knows anything about computers could look at this, I'd appreciate it.

AstroSynthesis 3.0 - System Requirements
Intel Pentium® IV class PC or comparable with 1GB (1024MB) RAM. 2GB (2048MB) RAM or greater recommended.
200 meg free hard disk space.
Microsoft® Windows 10, Windows 8/8.1, Windows 7, Vista, and XP officially supported.
A video card featuring OpenGL graphics acceleration.

AstroSynthesis is a 3D graphics application, so it is highly recommended you download the trial version to ensure there are no problems running the program under your specific video card and driver configuration.

FT3:

First some questions about particular functions within the program:

1. I've had issues saving content, specifically world settings (temperature, precipitation, mass of planet, etc.) and color settings (color gradients for elevation, temperature, precipitation, etc.). I haven't made any actual maps yet, just messed around and learned how things work. I can't save any settings in the directories where the program files are located, i.e., the default places to save, but I can save them in other directories that I choose. Is this because I only have the demo version right now?
2. In the "World Settings" window, in the "Editing" tab, you can specify a value for "Editing Size," either Small, Medium, Large, or Custom. What exactly does this control? Also, when I tried to change Editing Size from Small to anything else, when I went to a new tab and came back, Editing Size always reverted back to Small. Why does this happen? Is it just because I have the demo version of the program?
3. In the "World Settings" window, there is a tab called "Fractal Function," which apparently controls how the maps are drawn? I don't really know anything about fractals, and I don't expect anyone to explain it to me on this forum, but does anyone have any suggestions about which fractal function to use?

Now some more sciency questions:

1. In the "World Settings" window, in the "Temperature" tab, what physical quantity is "Greenhouse" exactly? I get that it indicates the greenhouse warming effects in the planet's atmosphere, but what specific physical quantity does it represent, and how do you compute it? The program tells me that Earth has a "Greenhouse" value of 1.1, if that helps. From GURPS Space, I've calculated a quantity called the "blackbody correction" for my planet, which incidentally also comes out to 1.1; this might be the greenhouse quantity FT3 is referring to, but I'm not sure. The funny thing is, in calculating the blackbody correction, you use a quantity called the "greenhouse factor," which obviously sounds like it could be FT3's greenhouse quantity, except that the greenhouse factor is about .16 for garden worlds. So I don't really know what FT3 is using.
2. In the "World Settings" window, in the "Temperature" tab, there is a quantity called "Light." Is this the same as solar luminosity?
3. In the "World Settings" window, in the "Temperature" tab, there are a set of three values collectively labeled "Physically-based Base Temperature." These three values are "Albedo," "Light," and "Greenhouse." When I input values for these three variables that I got from GURPS Space, I get surface temperatures in the hundreds of degrees Celsius. If I calculated these values correctly, I should be getting surface temperatures around 55 degrees Celsius. So what does this mean? Did I create my planet incorrectly, or is FT3 messing up? This is probably a really hard question to answer, so if no once can answer it, that's fine. Any insight at all would be helpful. If it helps, I got for my world an albedo of .13, a solar luminosity (light) of 1.8, and a blackbody correction of 1.1, which I'm currently using as my greenhouse value.
4. One of the most interesting things I've learned from FT3 is that, apparently, my world has quite a high rate of precipitation. Precipitation on my planet tends to stick close to 200 cm/yr, with oceans getting a bit more than that and continents usually but not always getting a bit less. In general, it seems that my world gets precipitation of 130-275 cm/yr. Between that and the high temperatures, the continents on my planet seem to be covered almost exclusively by tropical deciduous forests and some tropical evergreen forests, with no plains or deserts at all. My question is, does this make sense? What factors contribute to precipitation levels? My planet has an 85% hydrographic coverage (percent of surface covered by oceans). Could my high hydrographic percentage be related to my high precipitation rates?

So, that's a lot of questions. I realize that most people won't be able answer all these questions, so whatever insight anyone has to offer is appreciated.

And now Imma go to bed. Cuz it's 7 AM and I'm tired.

[waldronate]

I can probably answer the FT3 side of things as I am responsible for perpetrating that particular bit of software.

FT3:

First some questions about particular functions within the program:

1. I've had issues saving content, specifically world settings (temperature, precipitation, mass of planet, etc.) and color settings (color gradients for elevation, temperature, precipitation, etc.). I haven't made any actual maps yet, just messed around and learned how things work. I can't save any settings in the directories where the program files are located, i.e., the default places to save, but I can save them in other directories that I choose. Is this because I only have the demo version right now?

FT was developed way back when the Program Files directory wasn't protected. It tries to save its files into the install directory, which newer versions of Windows do not allow. I recommend installing FT3 into some location not under Program Files for best effects. This problem behavior is also present in the full version, not just the demo. This is the sort of thing that can happen with a piece of software developed back when dates started with "19".

2. In the "World Settings" window, in the "Editing" tab, you can specify a value for "Editing Size," either Small, Medium, Large, or Custom. What exactly does this control? Also, when I tried to change Editing Size from Small to anything else, when I went to a new tab and came back, Editing Size always reverted back to Small. Why does this happen? Is it just because I have the demo version of the program?

FT3 uses two main pieces of information to generate the final data fora world: a fractal field and user editing. You can paint higher mountains, more water, and so on using the painting tools. The Editing size is the number of editing samples across in the world (small=256, medium=512, large=1024). Note that these sizes are fairly coarse in the worldwide scheme of things, so I usually recommend 4000 or so. See http://www.fracterra.com/CGTutorial/index.html for examples.

3. In the "World Settings" window, there is a tab called "Fractal Function," which apparently controls how the maps are drawn? I don't really know anything about fractals, and I don't expect anyone to explain it to me on this forum, but does anyone have any suggestions about which fractal function to use?

The basic idea is that there is a mathematical function that determines the character of the landscape generated, with different function having different characters. I recommend using the "RMF with Perlin's Improved Noise" if present in your version. It has the best overall appearance and fewest number of bugs. See the referenced tutorial above for more discussion.

Now some more sciency questions:

1. In the "World Settings" window, in the "Temperature" tab, what physical quantity is "Greenhouse" exactly? I get that it indicates the greenhouse warming effects in the planet's atmosphere, but what specific physical quantity does it represent, and how do you compute it? The program tells me that Earth has a "Greenhouse" value of 1.1, if that helps. From GURPS Space, I've calculated a quantity called the "blackbody correction" for my planet, which incidentally also comes out to 1.1; this might be the greenhouse quantity FT3 is referring to, but I'm not sure. The funny thing is, in calculating the blackbody correction, you use a quantity called the "greenhouse factor," which obviously sounds like it could be FT3's greenhouse quantity, except that the greenhouse factor is about .16 for garden worlds. So I don't really know what FT3 is using.

It's the amount of temperature retention caused by greenhouse gasses in the atmosphere. A value of 1.0 means no greenhouse effect. The base temperature calculation used in FT is "374K*greenhouse*(1-albedo)*(light^0.25)" where * is multiplication and ^ is exponentiation. If I recall correctly, this formula came from "World Building" by Stephen Gillett [ https://www.amazon.com/World-Buildin.../dp/158297134X ] - page 67 if you'd like to check the assumptions.

2. In the "World Settings" window, in the "Temperature" tab, there is a quantity called "Light." Is this the same as solar luminosity?

Yes.

3. In the "World Settings" window, in the "Temperature" tab, there are a set of three values collectively labeled "Physically-based Base Temperature." These three values are "Albedo," "Light," and "Greenhouse." When I input values for these three variables that I got from GURPS Space, I get surface temperatures in the hundreds of degrees Celsius. If I calculated these values correctly, I should be getting surface temperatures around 55 degrees Celsius. So what does this mean? Did I create my planet incorrectly, or is FT3 messing up? This is probably a really hard question to answer, so if no once can answer it, that's fine. Any insight at all would be helpful. If it helps, I got for my world an albedo of .13, a solar luminosity (light) of 1.8, and a blackbody correction of 1.1, which I'm currently using as my greenhouse value.

You have a world a third the brightness of Earth receiving twice as much solar radiation. Those high temperatures seem reasonable under those conditions. A simpler solution is to pick your desired base temperature and go with that. Adjusting the physical parameters is fairly squirrelly and it's hard to get useful results.

Note that there isn't any parameter for orbital radius here, which will have a huge impact on your results.

I have not looked at the GURPS Space stuff for a very long time, so I don't know what the assumptions of their computations are, sorry.

4. One of the most interesting things I've learned from FT3 is that, apparently, my world has quite a high rate of precipitation. Precipitation on my planet tends to stick close to 200 cm/yr, with oceans getting a bit more than that and continents usually but not always getting a bit less. In general, it seems that my world gets precipitation of 130-275 cm/yr. Between that and the high temperatures, the continents on my planet seem to be covered almost exclusively by tropical deciduous forests and some tropical evergreen forests, with no plains or deserts at all. My question is, does this make sense? What factors contribute to precipitation levels? My planet has an 85% hydrographic coverage (percent of surface covered by oceans). Could my high hydrographic percentage be related to my high precipitation rates?

See the above-referenced tutorial for a short discussion on the limits of FT's climate model.

[johnvanvliet]

A video card featuring OpenGL graphics acceleration

and you have a AMD "HD 8770M"
ADM is notoriously OpenGL hostile and Microsoft is VERY VERY VERY OpenGL HOSTILE

normally Microsoft will DISABLE openGL code in the drivers installed bu windows Updates

uninstall the MS provided amd driver and install the one from the AMD web site

[EpicBradley129]

Thanks for the replies guys!

@ waldronate

You, sir, are the best. Your response was very thorough and answered all of my many questions, and I appreciate that.

I used the base temperature calculation, and apparently my world actually has a greenhouse value of .87. I'll have to look into that, because I've made my planet hot with high CO2 levels with the intention of putting it into the early stages of a runaway greenhouse effect. So, yeah, something's not working, which isn't really that surprising. I also don't understand how any formula for the temperature anywhere on a planet can not take into account the planet's distance from its sun and still be valid. I suppose it must assume a certain orbital distance? Well, in any case I took a look at the book you linked me too, and it looks amazing so I bought it. So double thanks for that, and hopefully I'll be able to answer some of these questions in there.

@ johnvanvliet

Well that's unfortunate. I may hold off on purchasing AS3 until I actually need it then, and when I do install it I'll post back on this forum to make sure I'm uninstalling and installing the right drivers. Thanks for letting me know about this problem.

[johnvanvliet]

Amd ( well ATI ) is getting better but they were a Windows DirectX ONLY!!!! shop for so long , it is taking time to get up to speed with OpenGL ( nvidia developed it, mostly )

and MS has been known to disable some / parts of OpenGL in the drivers they redistribute
MS even took nvidia to court clamming "copyright" violation on opengl
and MS has been on a 15 year crusade to KILL OFF OpenGL as it is a rival to DirectX