Terraforming
From #openttdcoop wiki
Terraforming is a difficult thin in #openttdcoop games. Sometimes we try to build our networks as realistic as possible without any too big changes on the landscape using the given geography of tales and mountains. In other games we flatted everything due to the most effective network buildings like massive stations with big and fast entrances. Both ways of gaming are in their way interesting and therefor you should stick to the definitions made in this article.
Before a game starts a !network plan will be created, things like train length, network layout and the kind of game will be discussed and finally planned. One part of this discussion is the way of 'terraforming'. We have several grades how terraforming should be used in the game and if I miss something here, please add it.
Terraforming doesn't matter:
In this case everything can be done as you like. Feel free to flat the landscape to your needs.
Coop-Terraforming
If playing with coop terraforming a lot of landscaping can be done if it is needed for our network. There is an aspect of the good look and feel, but the functionality is the most important thing. In fact it is more important to provide a network (with all its buildings: Hubs,Entrances,Exits,LB and so on) which has a high capacity/no jams instead of having an eye-candy like network. But anyway you should keep that aspect of the good look in your mind.
Low-Terraforming
This is often misunderstood and people think its No-Terraforming. This style is vice versa to coop-Terraforming. The network layout will be created according to the given landscape. You should use mountains and tales and create eye-candy tracks. The use of tunnels is quite important, because in reality trains use often tunnels instead of going over a mountain. The priority of the good look and feel is higher than the capacity and speed of the network. Anyway there are games which have also a high capacity, but that takes a lot of time (Werkloze Desyncs, Inc.)
No-Terraforming
This is not possible, is it?