The growth of the scenes in 3D games makes the manual modelling very expensive. The mobile platforms – because of their different business model – do not let very expensive games to be created. Procedural scene generation could be a solution for both problems.
The aim of this paper is to procedurally create the unique sight of the streets in North American cities. Brick houses are needed which can be found either in Manhattan or Bro-oklyn, or in many other American cities. These houses are usually 4-5 stories high, have simple windows and there are shops in their groundfloors. These houses are good for procedural generation because of these properties.
There are many algorithms and technologies to generate three dimensional scenes. It is possible to create landscape, trees and foliage, streets, buildings and textures with these procedures. This paper lists the more important ones, than shows how to build up a proper city with Wang tiling, Wing Edge data structure and Perlin noise.
Even though Wang tiling is mainly used for texture generation, in this paper it is used also for dividing the road network of the city. The tiling is also used in texture generation, because many brick walls are needed. These textures are not statically used, but dynamically generated by the shaders of the graphics hardware.
The Relief mapping is also implemented as a shader program, which turns the simple flat surfaces into good looking three dimensional geometry. With its help, the windows are placed behind the surface of the wall, and the bricks move forward from the pointings.
There are many graphics engines and frameworks, and this paper uses Unity 3D to show how it is possible to proceduraly generate the scene of a multiplatform three dimensional game.