The aim of the World project is to create a complete and complex 3D environment only using procedural generation techniques. Everything is procedural: geometry, materials, textures... No assets, only code!
As we want our world to be huge, but also finely detailed, World implements LOD support. You can go as far as you want, but also as close as you want.
Procedural generation enables you to tweak the parameters as you wish. As World relies solely on procedural generation, everything is configurable. You can therefore build a world that fits your needs or explore the vast amount of possibilities by changing the parameters.
World is built as a library, so it is easy to integrate in other programs, and it can perform offline assets generation that can be edited on 3D software like blender.
Currently World can generate terrain, including mountains, plains and oceans, but also trees, grass, rocks...
For good quality 3D environment, procedural techniques should be used in combination with assets made by artists.
World is a challenge, it does not aim to be as good as what an artist could produce. But procedural generation brings an other great feature: diversity. This library will eventually (hopefully) be able to generate worlds that you can explore endlessly. With species and biome generation on the fly, we can achieve continuous surprises and new unseen landscapes.
World needs to virtually generate an infinite amount of objects in space, but also infinite level of details. Of course we can not store an infinite amount of objects nor generate it in finite time. That's why World generates only what is needed.
The structure of the world is a graph where the nodes are generators of a little part of the world. The nodes are not 3D objects or meshes, but rather contain information about how to generate the geometry and the texture at different level of details. What is generated then depends on the position of the observer when they explore the world.
When a world is initialized, it contains few if not any nodes. New nodes are generated during exploration by an entity called Decorator, that will populate the regions when they are discovered for the first time. Some nodes also generate children nodes to add an additional level of detail for example.
Resolution Models describe how a user sees the world by associating a resolution to every point in space. For example, a "first person resolution model", would associate high resolution to a point near the player, and a very low resolution to a point far away from the player.
To make the library generate assets for a part of the world, you have to explore it. The resolution model will be used to determine which regions need exploration. The result of the exploration (ie. the generated assets) will be stored in a Collector. The collector has multiple channels that can store different types of assets, going from meshes to materials and even shaders. Usually the collector also retrieves "scene objects" that hold information about the scene organization: how the objects are positioned, what materials do they use, etc.
Once the collector is filled with all the generated assets, you can just iterate through the list of all the scene objects, add them to a game engine scene for rendering and voilà!
Due to its generic structure, World can have a large variety of uses. You can use it to generate a complete game environment in real time, but also only parts of the environment. You can even use World as a part of your workflow, by generating the environment and then refining it manually. Or you can chose to only use one module to generate trees or rocks for example.
World is a cross-platform library, available on Linux and Windows. The idea is to make it compatible with as many tools and languages as possible. Currently, you can use it in your C++ project and also as a (still limited) Unity plugin. You can also export the generated assets into an .obj file to open it in your favorite 3D software.
In the near future a JSON API will be developped to ease the interoperability between the core library and any application. Python bindings are also planned, as well as other export formats for the 3D scene.
Update 0.4: JSON API is finally here!