I haven't played the last SimCity, but I remember from the old games (i.e. SimCity 2000) that you had these maps showing pollution, wealth, energy, water, etc. And I guess other games like GTA used the same technique. Now from a first person perspective, the entities that the player finds in the city will reflect the conditions given by these statistical maps. For example in a polluted zone there will be more garbage or fog in the streets, and a wealthy zone will have more luxury houses and cars. I'm exploring ways to use this concept to simulate a massive ecosystem. If there is a river and mountains in a map, the influence of water on vegetation could be mapped so that there will be higher tree densities. Then vegetation levels will influence density of herbivores. Now, resources are static and rather easy to map, but then vegetation could be harvested or catch fire, then it will be dynamic. And animals could migrate and increase/reduce population due to mating seasons and plagues. It's like a complex version of Conway's Game of Life, and not all "masses" have the same pattern. What techniques exist to process such system? What optimizations could be performed, having in mind that the system could have no constrains?