Celestia Forums

I know it sounds stupid but I was wondering could you build a game around the celestia code? I was searching for an engine to build Battlefleet Gothic on.

In principle it should be possible, but nobody has actually carried it through to completion yet. E.g. "Mostly Harmless" is one person's attempt, but the author disappeared before completing it.

Otherwise, does there exist an open source game engine with which Celestia could be coded with?

For example, the Quake 3 engine source code is public, why not build Celestia with it?

Celestia seems it could be exactly what I've been looking for. What 3D program works best with celestia? And does anyone know where to look for Battlefleet Gothic models?

Thanks

Zaldurak,

Any 3D design program that can export 3DS format is fine. Export scripts are available for Blender and Anim8or to write Celestia's native CMOD format.

There are a couple of people posting to scifi-meshes.com who have made Battlefleet Gothic models. You might ask there.

FaLLeN_SOuL,

Celestia doesn't use a game engine because it's written in C++, which is available on all modern computer platforms. Why add another layer of software with its own set of bugs? On the other hand, if you want to write your own multi-platform 3D visualization program based on gaming software, I'm sure there are plenty of people who'd be delighted to try it out.

I would certainly be delighted about such stuff. Zaldurak, I wish you the best of luck with your efforts.

FaLLeN_SOuL wrote:Otherwise, does there exist an open source game engine with which Celestia could be coded with?

For example, the Quake 3 engine source code is public, why not build Celestia with it?

Different 3D engines are suited to rendering different types of environments. Quake 3 would not be at all useful for Celestia, because it's optimized for building interiors rather than vast, mostly empty space. Most of the graphics code in Celestia exists to solve problems that don't come up in a game level. For example, the precision issues that arise from the scale discrepancies in a scene with a tiny spacecraft and a gas giant planet.

--Chris

So celestia would be hard to use as a game platform cause of size issues? If so then what would you recommend?


Thank you

Zaldurak wrote:So celestia would be hard to use as a game platform cause of size issues? If so then what would you recommend?

That's not what I said at all--I only said that the Quake 3 engine would be inappropriate for Celestia.

--Chris

Oh Ok Im sorry for the misunderstanding. I was thinking along the lines of a space fleet RTS or turn based game set around celestia code. But I cant seem to get any of the models to work in celestia tho they were DL from here. Any suggestions would be greatly appreciated.


Thanks

To me all this talking looks like planning a marriage between a beautiful girl and a chimpanzee

Let me just add that for game programming, the huge effort we made in Celestia towards realizing unique astronomical precision is a total overkill and just eats up resources needed for the game engine.

While pairing Celestia with a game is certainly possible, it was never designed/meant to be part of a game.

Bye Fridger

Zaldurak,

Some older Addons need to be modified before they can work with the current version of Celestia.

If you haven't already done so, please read at least the introductory section of http://www.lepp.cornell.edu/~seb/celest ... intro.html
which tries to explain how Addons should work.

t00fri wrote:Let me just add that for game programming, the huge effort we made in Celestia towards realizing unique astronomical precision is a total overkill and just eats up resources needed for the game engine.

Thats kinda harsh Fridger since my main complaint with most games these days is the lack of realism

Rassilon wrote:

t00fri wrote:Let me just add that for game programming, the huge effort we made in Celestia towards realizing unique astronomical precision is a total overkill and just eats up resources needed for the game engine.

Thats kinda harsh Fridger since my main complaint with most games these days is the lack of realism

Come on... during a game nobody will ever have the time (and motivation) to check whether Jupiter's position is accurate to < 1 arcsec!! Or whether this partial eclipse of Europa - Calisto happens 1 second too late

Bye Fridger

I think a program like celestia would be really helpful to gamers, to help them get a sense of just how vast the universe is. But Celestia could not be the program for my game. Im just saying that there is alot of games out there that makes you feel like a big fish in a small pond.

Zaldurak wrote: ...I'm just saying that there is alot of games out there that makes you feel like a big fish in a small pond.

Exactly! Celestia and game engines have nothing in common.
Generally, game engines render current action in a finite (read small, equivalent of a couple kilometers in game units for really huge maps/levels) volume carved in a solid block of nothingness.
Anything which has to be rendered outside the action volume is created in a skybox that is unreacheable for the actors in the level/map.
The skybox was invented as a backdrop, just for that: give a feeling of something else existing outside the current map/level: sky with clouds to begin with, obviously, outer space with stars, nebulae and planets or other objects like mountains far away.
Skyboxes are mostly simple empty volumes with some texturing on the walls and billboards if present, with some lighting added to it.
They are not supposed to host models, but they can. A model in a skybox is a fps killer, though.

Does Celestia have a game potential?

IMHO Yes of course. But its not so easy.

To create a wonderful game using Celestia the engine lacks only of a few things. At least:

- Collision detection
- Simplified Gravity simulation
- 3D planetary surfaces
- Full OpenGL UI
- A bit of random generated detail
- Improved shadows on models

Take a look at this game as an example:
http://www.fl-tw.com/Infinity/infinity_overview.php
http://www.youtube.com/results?search_q ... rch=Search

Specially to the official combat prototype 2.1 and the planetary surface demo.

Kind regards

I'd actually venture that a full Newtonian physics simulation in the game is not what players want or expect. In my experience, people can cope with a "Star Wars physics" game (basically, the spacecraft fly as if they were aircraft) far better than a realistic Newtonian physics one. Definitely in my experience, the "Star Wars physics" games are more fun to play.

And, of course, if you want a spaceflight "game" with realistic Newtonian physics, there's always Orbiter.

For those who want to know how a skybox is working, I have made some screenshots of a map I made for Unreal 2004.

/!\ beware large pics inside!

The first pic shows the 3D editor in action.
On the right side, there are wireframe previews of the ship model enclosed in its hexagonal container, and of the skybox in its own cube carved out at a distance from the ship's container:


The second shot shows a close-up of the skybox in wireframe mode:


The third shot shows the skybox textured and lit:


The two last shots have been taken in-game in spectator mode to show the skybox in action.
Many textures and lights are procedurally animated:




From an observer's perspective, the skybox is seen as completely wrapping the scenery, as if the ship was at its very center.
The ship is huge, equivalent span of some 150 to 200 metres with a total heigth of some 800 metres.

Some 16 players can happily frag inside and around the ship