City-Building Overview

We really appreciate your ideas and efforts to model additional content to make our virtual cities more interesting. If you have further questions regarding modelling, don’t hesitate to contact us at citybuilding (at)

General background

Twinity consists of three main parts – avatars, the inner world and the outer world. The outer world is everything that can be seen in the Twinity cities. This includes buildings, landmarks, public infrastructure, vehicles, city furniture, trees and vegetation.
  • City furniture includes all the small items in a city. For example public seating, advertising-signs, bus-stops, fences, construction sites, phone booths, facade applications, waste bins, lamps, cars, dirt and bushes.

  • Landmarks are defined as special, unique and often very complex buildings, memorials and fountains, which cannot be visualised by procedural city building. Other than city furniture, landmarks can usually only be used in one unique place.

    If you like to model a landmark, please be economic about the model size. Most of our landmarks consist of about 4.000-30.000 triangles. If your model has more than 10.000 triangles, split it into smaller pieces, which can be placed together. Remember the viewing level. Parts above 3m height above surface can be done with less detail. You will need to create two simplified LOD-versions for rendering from a distance and a collision mesh for the model (see guide on city furniture for details).

  • Standard buildings like residential buildings in our virtual cities are created with our special, in-house city-building software called AGIS. Creating facade styles for buildings needs advanced modelling skills and some secret, dark magic, which obviously cannot be explained here.