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[cerapa]

If you are new to the thread, this is the latest general state of the game:








Perhaps some of you remember this from 6 months back. Well, I am back to working on it, and it now has more less features than ever before! Rewriting the whole thing cause making buttons is "too finicky" tends to do that. And then after finishing, porting the entire thing over to SDL2. And then playing lots of CK2 and EU4. And then...actually working on it.


Is the current result. At least of the star generation, since this is just a mockup display I did for debugging(white boxes are raw data, blue boxes passed data, actually did identify a bug using this). The current display(not the one in the picture) is a bit(read: very) raw at the moment. Cause I'm horrible at making graphics(painting side, not coding side).

Iron Star, will hopefully be a space grand strategy game, heavily inspired by paradox titles(except in Space!). Space is infinite, deterministic, and generated when needed. Most things are randomly generated, which includes planets, resources, and the galaxy. Gameplay will involve colonizing new planets to get better and more resources and fighting off colonial revolts when they decide that they don't want to give you all their stuff.

If you want to take a look around then here is a Download Link. Drag to move around and if you notice any slowdowns, or broken mouse detection then let me know. I use yellow as the debugging shorthand for the mouse being over something. Clicking on a star opens a window that you can drag around and close, which is just a placeholder for an actual star system view window.

At the moment I actually have some stuff done on the planets(half-cannibalized from before the rewrite). Once I've finalized my thoughts on generating star systems, then planets will in part already be ready to go.


So stay tuned for future updates and ask if you have any questions. Also would appreciate anyone willing to work on the graphical side of things.

[mastahcheese]

I tried to download, but it said I don't have the right program to run it?
Otherwise, this looks cool.

[cerapa]

I tried to download, but it said I don't have the right program to run it?
Otherwise, this looks cool.

Ah, I'm guessing you don't have 7zip.

Here's a regular zip file you should be able to unpack.

[mastahcheese]

Yep, got it now.
Looks cool, so far.

[cerapa]

Yup. Still in C++.

Sadly no updates right now. I can't seem to get a handle on the way SDL spins textures.

[cerapa]

Spoiler (click to show/hide)

Yay, graphics. The blue thing does a spinny thing when you mouse over a star. Looks better in motion than in the screenshot.

Anyway, gonna implement star system genning now. I'm not particularly well versed in the particulars of stars, so for now stars only have a single stat of luminosity, which determines if the planets around it are frozen wastelands or big balls of lava(with a decent degree of variability of course). Maybe some planets will even be in a hospitable range, who knows?

Most stars will have 2-3 planets and 1-2 asteroids. Not that it really matters, it's an easy enough thing to change. Moons will not be in.

Why am I wasting time posting this anyway? Spent enough time playing starcraft already. Will hopefully have more interesting things to show tomorrow. Off to work then.

[wierd]

YAY! Science!

Spoiler (click to show/hide)

The mean surface temperature of a planet is the product of the amount of energy being delivered to the surface and atmosphere, weighted against the rate that the energy is released in the form of radiant IR energy. Different materials have different rates of absorption and release of this energy, which is known as their specific heat. (How many joules of energy are needed to raise a single gram of the material one degree centigrade. The definition for the units in science on our planet, is that 1 joule of energy is required to raise 1 gram of pure water 1 degree centigrade, IIRC. Other materials have different absorption and thermal reaction rates.) You then also have to model in the rates of thermal conductance of the materials, and model material mixing and the like.  YAY, now you know why climate models are "Hard"!

We dont really need to model a planet down to that level of sophistication though. We can just average out the surface and atmospheric compositional elements based on thier concentrations, and then simply ignore non-solar forms of heating when performing the mean surface temp calcs, using only the planet's diameter, distance from star, and intensity of solar output in joules per square centimeter. We would do this using basic trigonometry and a very coarse estimate of the planet's total insolation (light hitting the surface, based on angle of incident.)   

Orbital information would play a significant role here, as the degree of insolation is directly proportional to the inverse cube of the distance the object being irradiated is from the radiation source, and orbits with an eccentricity will cause seasonal variations on this. Possibly quite radical ones. (see for instance, "Hot Jupiters" that have been recently discovered.)

It should be possible to work out a highly generalized formula for average surface temperature based on a more complete derivation from the above, where your inputs are simply "Compositional mean specific heat", "Distance from star", 'Diameter of planet", and "insolation at 1AU" for the star.  3 of those will be constants for the planet, and the last, distance, will be variable, due to its orbit.

Orbits can be reasonably computed using JUST their velocities/periodicities, and their masses in relation to the mass of their star, and each other, using Newton's law of universal gravitation. (Essentially, gravitational attractive force falls off in the inverse square of distance between the centers of mass of the objects exerting the force on each other, as measured at the barycenter of their attraction.)

If you dont mind doing a little heavy lifting initially to make the generalized function to call, you can make some pretty neat random systems this way.

[cerapa]

Ah, an excellent explanation. Wasn't really planning on putting in eccentric orbits, as the game will be turn based, and if orbital season length does not coincide with the turns, then you would get odd behaviour, like skipping the coldest part of a highly elliptical orbit, and thus invalidating the entire reason for such a system.

Right now the thought is to have a number of orbital distances(1, 2, 3, ect, so I wouldn't have to adjust planets that should rightfully crash into eachother) that planets would be in, which in combination with the star and the planets atmosphere determines the heat of the planet.

What are the general effect of these factors? How hard does heat drop off with distance? How much does the diameter change the heat of the planet? And what's the difference in heat between say a planet with Earths atmosphere and an equally sized atmosphereless planet with an equal distance to the Sun?

[My Name is Immaterial]

Very cool looking. I'll take a look at it later.

[wierd]

Very large.

Earth with no atmosphere would be very much like earth's moon. 107c in the sun, due to high albedo, and minus 150c+ in the dark. The earth and the moon have very similar surface material compositions, which have very similar average specific heats. The difference is that the earth is wrapped in a warm blanket of greenhouse gasses. (Water vapor being a major contributor.)

On a planet with an atmosphere, the light striking the surface has interacted partially with a very large column of gas overhead, which robs a good deal of the delivered energy from the light before it hits the ground.  So, on earth, the light is strong enough to raise the temperature of the top few inches of a lake several degrees celcius, but without that atmosphere in the way, radically more inense light hits the surface.  That's why the moon is roasty toasty in the sun (and why astronaughts need gold plated visors!), and colder than a well digger's ass in the shade, while still being quite happily placed in the habitable zone of our star.

This is why I suggest combining the specific heats of the surface and atmosphere to get the surface temperature. That way this effect is baked in. A planet with no atmosphere will just have the surface mineral specific heats, which are radically different from the gasses and vapor droplets in an atmosphere.

(Hint, toady already dug up a bunch of specific heats for common crust minerals, and the data is inside DF's raw files. )

[Skyrunner]

....but in Urists, aren't they?

[wierd]

The converter is just one line of code. The wiki gives the formula.

*shrug*

It's still easier than hunting those all down.

[cerapa]

I would like to note that I am not going to generate a planets surface material composition.


^{(Ignore the IIIIIIIIAAAAAAAAAAAAAAAA..., that stuff is just for debugging,  SDL_RenderSetClipRect has a bug in it, that can apparently be fixed by setting the width to be (width+x)/2)}

I now have the framework for doing whatever the hell I like with the system display, which would be excellent if I was actually good at UI design. As I am not, I will be leaving it at this for now. You just click on the name of the planet to open the planet view.

And the planets are actually in the correct order, sorted by distance from the star, which I currently simply aren't displaying.

EDIT:
Now with sexy scrolling action. Just click and drag.

[Omegastick]

This looks really really cool, I'm looking forward to seeing where this goes. Keep it up!

[cerapa]

Download

Behold, Iron Star v0.002. You can now click on the stars. Which opens a window with a list of planets. Click on one of them, and wait until the console happily proclaims that "It's ALIVE!", then click on it again, the map(just a heightmap at the moment) should then open. You may try scrolling if aren't afraid of summoning Cthulhu. You may close it by clicking top left, you can tell the right place by it turning yellow when moused over.

You can do many other interesting things as well, like see how many planets you can open before the game crashes from running out of memory. Or scrolling on the galaxy map until the game runs out of planetID's.