The seditious ideas on how to use vector maps as in-game maps

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Lets consider how you can use vector maps in games creating and what difficulties can be in this.

Current state of affairs

The game map of the world is an essential element of many video games of various genres. But even in the most advanced in the technical plan and popular games we see rather low detailed in-game maps. The map is especially important in games with a huge world, where the player need constantly determine his position in the world on the map. In many massive multiplayer online games the game map is a plain image of relief viewed from above and very uncomfortable. There is a natural and long overdue transition from image-maps to high detail vector maps.

On the other hand, if maps must depicture a large territory (even an entire planet) and/or has a high level of details, then the procedural generation of maps has no alternatives. Always keep in mind, that the generated map can always be supplemented with new details or it can be edited manually.

For many standealone and online games, there are map generators. But such generators are designed to produce small-detailed tile maps or each generated world is monotonous and does not correspond to the spherical geometry of a planet. While in massive multiplayer games, because of the difficulty of manually drawing large and detailed maps, game-devs prefer to use the same image of the world for unrelated gaming servers. And the emergence of another world is appeared as a very big event. With procedural generation new large and detailed worlds will become an ordinary event. Furthermore, it will be possible to make the games with a mechanism for generating or loading standardized in-game maps, and the action of different games can occur in the same world. As a universal map format, I propose to use the generally accepted data formats of modern GISs.

Relief (terrain)

The terrain in many games is an integral part of them and the map of a game world is in interrelation with the terrain. During procedural generation of maps, one can build the map on the existing relief (as it is done in this project), consequently the relief and the map will be naturally related.

Output relief data of the project is represented by SRTM hgt data. SRTM data format represents a heightmap, while in the most games the relief is some polygonal mesh. Therefore, the first difficulty is the translation of a heightmap into a polygonal mesh. The most likely solution is to use a heightmap as a base mesh, which can be supplemented with details during the transition to a polygonal mesh. In this case, if details added are smaller than the size of small details of the original relief, then no map adjustment is required.

The presentation of data in the SRTM has a major drawback; it consists in the fact that the data density is changing with the latitude. But we have the entire accumulated arsenal of available tools for SRTM data format. The project internal binary representation of the data that depends on the division of the planet’s surface into rhombuses is nowhere else accepted, so currently I prefer SRTM as the output format.

Vector map

Vector maps are not only provide an opportunity to highlight every detail of the world, but also the ability to change the world itself. And thus, the emergence of games in which the world itself is not only a background, but an active element of the game is possible.

I will give several possible examples which seem to me quite feasible today.

  • Apocalyptic games of various genres. The relief and map change with the development of events: craters and volcanoes appear, continents are flooded or rise.
  • Geographical discoveries. Geographical features are multipoligons and have strictly defined coordinates.
  • Multiplayer strategies. Players themselves arbitrarily set the boundaries of their states, and do not transfer pieces of territory pre-set by a game designer manually. Trade routes can go along rivers or arbitrary roads build by players.
  • Multiplayer role-playing games. Players can build houses, fortresses, dig channels and generally change the face of the world. Player’s home houses or guild’s HQs can be finally placed on the map.
  • Many other types of games with a huge world. One or all of this: the great extent and the variety of the game world, the possibility of terraforming and changing the world itself, really spherical world.

Map presentations

Since the maps are obtained with the help of GIS and are made for GISes, various manipulations with the map are permissible, as well as various representations of maps. What you can see on this site in the section of free maps is by no means the final appearance of maps. You can use different color representations and map types of your choice.

The color style of the free maps on this site was made in the TileMill tool, with the following generation of map tiles with Mapnik.

If you were interested in maps creation, then probably you are familiar with the hillshading type of earth maps. Such a representation of maps can be made with the maps obtained with the project, but in my opinion, satisfactory hillshading maps will be received only when higher resolution maps will be enabled in the project.

Also, by the means of gdal library, you can draw a contour height map (as in a topographic maps). But applying them to the SRTM data of an entire planet can require a very long run time. In my plans to make the height contours in the project itself. Obtained contour data will be included in the standard supply of the planet’s data.

When using the Web Merkator projection area near the poles are strongly stretched horizontally. But it is always possible to choose a different projection, in which the selected territory will have minimal distortion. As an option, it is possible to divide the world into pieces with less distortion (with a suitable projection) and display the map parts instead of the full planet map.