Game Design student asking for information about the engine

[Fazaam]

Hi !

Please allow me to introduce myself, Nicolas, 20, student in Game Design and Production Management in Supinfogame (France).
For those who haven't read the "Hello post", I'll introduce the context.

I'm currently in my 3rd year in this school. Our fourth and last year is dedicated to the design (conception) of the game and development of a playable prototyp of the game. Groups have just been formed, and I'm responsible for the technical part of the project.

While searching for engines that would fit our needs to develop the game (When Gods play -Working Title-), I was sent on your website and saw that Glest's engine would probably be a great help for the development.

That's why I have some questions I would like to ask you, and I hope you'll get the time to answer it.

1. Legal's rights

• Is the engine fully open source ? May we use some parts of the Code without the rest of the engine ? Can we use (for example) a function out of context without any issue ?
• Is there any restriction about using the engine (except selling, ofc)
• Do we need authorizations for specific things ? Are some things forbidden with the engine ?
• Does some libraries used have differents licence's restrictions than your engine ?

2. Technical's issues

• What are the limitations with 3D and number of polygons ?
• Does the engine support pathfinding modification in real time, on independant units ?
• Would the engine be able to be modified to support ground modification during games ? Considering that these modifications are decided by the players.

3. Multiplayer's issues

• I saw Glest is limited to four player in the same gameroom. Is that a game restriction or an engine restriction ? Is this restriction irrevocable using the engine ?
• Do you think there would be any compability's issues while trying to use the engine with a persistant world server ?

Thanks to those who gave time to read my questions, and thanks to those who tried, but couldn't xD

Greatings,

Nicolas.

PS : If there are any need for further information, or any question relative to the project, you can both post here or ask me privately.

[John.d.h]

I don't know the answers to all of your questions, but I'll answer the ones that I can.

That's why I have some questions I would like to ask you, and I hope you'll get the time to answer it.

1. Legal's rights

• Is the engine fully open source ? May we use some parts of the Code without the rest of the engine ? Can we use (for example) a function out of context without any issue ?

Yes, every part of Glest is licensed under the GNU General Public License.  You can use any part of it that you want.  This means that you can use it, modify it, do whatever you want with it, even sell it, as long as you give credit to the creators (i.e. The Glest Team) and that it remains open source.  This includes the program code, the models, the images, and all other parts of the Glest game.  For a full explanation of the GPL, look here: http://www.gnu.org/copyleft/gpl.html

• Is there any restriction about using the engine (except selling, ofc)

The only restrictions are that you give credit to the Glest team for using their creations and that anything you develop with it remains open source.  The rest of your game (anything you develop on your own without using any Glest content) can be licensed however you want.

• Do we need authorizations for specific things ? Are some things forbidden with the engine ?

No and no.  You can use any part of it you want.

• Does some libraries used have differents licence's restrictions than your engine ?

I'm not sure what you mean by that, so I'll let someone else answer this question.

2. Technical's issues

• What are the limitations with 3D and number of polygons ?
• Does the engine support pathfinding modification in real time, on independant units ?
• Would the engine be able to be modified to support ground modification during games ? Considering that these modifications are decided by the players.

I can't help you with the first two points, but ground modification is something that's in development for GAE.  If you don't know what GAE is, refer to the following thread: https://forum.megaglest.org/index.php?topic=3229.0

3. Multiplayer's issues

• I saw Glest is limited to four player in the same gameroom. Is that a game restriction or an engine restriction ? Is this restriction irrevocable using the engine ?
• Do you think there would be any compability's issues while trying to use the engine with a persistant world server ?

The developers of GAE are currently working on a way to allow more players.  Refer to the following thread: https://forum.megaglest.org/index.php?topic=4266.0
I don't know anything about servers, though.

Thanks to those who gave time to read my questions, and thanks to those who tried, but couldn't xD

No problem.

[Fazaam]

Thanks for your fast answer :-)

To explicit the question about libraries, I was talking (for example) about the Open GL API, I don't know if the legal restrictions (or unrestrictions) are the same than for Glest.

Thanks again !

[Fazaam]

Sorry to upgrade the post, but there are some questions that haven't been answered, especially about technical issues (polygons & realtime pathfinding modification).

Is there anybody out there that could answer it ?

Thanks,

Nicolas

[hailstone]

In 2004 it was about 500 polygons for units and 1000-2000 for buildings (see post). I don't know of any rigorous testing done.

The library links are listed at https://docs.megaglest.org/Compiling if you want to check the licenses for each.

Does the engine support pathfinding modification in real time, on independant units ?

If you mean select a unit then click to change its path then yes or do you mean the Supreme Commander style waypoints?

Do you think there would be any compability's issues while trying to use the engine with a persistant world server ?

Depending on the server and your requirements of it you might need to modify the source extensively. This hasn't been done with Glest so it's not really known.

[wciow]

In 2004 it was about 500 polygons for units and 1000-2000 for buildings

My dwarf mod is using unit models between 1000-1500 per model and 2000+ for buildings. The texture sizes are mostly 1024x1024 rather than the 264x264 used for original glest models. I can run it flawlessly on my pretty old hardware and I haven't heard of anyone else having problems.

I would think these figures are pretty much on par with modern RTS games, however Glest still lacks alot of the extra eye candy you might find in modern commercial products such as specular/normal maps,true unit physics and sync animations. 

[Fazaam]

Thanks for both of your answers !

It seems to be quite good and enough for our graphics' requirements.

Does the engine support pathfinding modification in real time, on independant units ?

If you mean select a unit then click to change its path then yes or do you mean the Supreme Commander style waypoints?

I wasn't enough clear i guess.
In our game, units move alone, and the player can only influence them by modifying the environnement. (For example, create a river, etc.)
Then, that's why this question is that important. We would need our code to modify units pathfinding everytime something is modified on the field.

So the question here was to know if Glest's engine would support it easily, or probably crash because it's too much to ask

Thanks again for your help,
Nicolas.

[hailstone]

I did a small test by getting a unit to move in a path then building a building in the path of the moving unit. It recalculated the path fine. It might work differently for the terrain. I assume that if the unit can't go on the path it tries to recalculate. I'm not sure if it would crash or slow down with many units recalculating paths but the only way to know is to try.

[silnarm]

I wasn't enough clear i guess.
In our game, units move alone, and the player can only influence them by modifying the environnement. (For example, create a river, etc.)
Then, that's why this question is that important. We would need our code to modify units pathfinding everytime something is modified on the field.

So the question here was to know if Glest's engine would support it easily, or probably crash because it's too much to ask

Glest recalculates paths whenever necessary, if the original path was into unexplored territory and the unit encounters an impassable object the old path is thrown out and a new one calculated. If another unit gets in the way, a new path is calculated, whether this be another moveable unit or a building that wasn't there when the original path was calculated.

I just ran a quick game and collected some stats,
     4162 A* Calls, 879 of them recalculations.

Glest's Path Finder is not very quick, and it's absolutely terrible for long paths. The path finding in Glest at the moment is in need of an overhaul... hopefully it will get one soon

As to your needs, it will depend on your map size and typical path lengths, and how intelligent you want it to be... the Glest pathfinder can be 'hobbled' via PathFinder::pathFindNodesMax to make performance a non-issue, but it gets a bit 'dumber' because it's just doing a long path in segments, and it's not actually all that smart to start with