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Forestry - a guide to cultivating trees and hedges
This tutorial takes a look at placing trees in GenesisIV, both as forests and in hedgerows. GenesisIV offers two methods of adding vegetation to landscapes, either using ecology - where vegetation is placed across the whole landscape according to rules, or terrains, where vegetation is placed using polygons or lines. This tutorial concentrates on the latter.


We'll start off by adding a simple terrain polygon to a sample landscape. The image shows the heightfield editor open with the vegetation terrain selected for editing. By clicking on the polygon tool (green quad in the toolbar) the user has added a simple area to the landscape as shown by the transparent green patch.

  
To start with we'll add one tree type at low density. Open the terrain layers editor (accessible both from the main screen and renderer windows), select the Vegetation terrain layer and the vegetation tab. Set up the plant types so that only one plant has a density value greater than zero.  

Render the image at fractal level 2 or greater with the 'Draw Vegetation and Models' check box selected. A small number of trees are shown randomly distributed around the terrain area.

Note that vegetation is not displayed at fractal level 1 or less.

  
Reopen the terrain layers dialog and select the vegetation layer again. Increase the density values and this time include all four vegetation slots.  
This time our forest is shown at much greater density, with a mix of trees. Note that a certain amount of height variation is used for each tree to make the forest look more natural.  
To generate a simple hedge open the terrain layers box again and check the 'Draw on polygon edge only' box. Note that for hedges it is advisable to increase the density of the vegetation.  

The rendered image shows a hedge around the terrain area.

This method works well for simple hedges, but more complex landscapes are best achieved using a combination of lines and polygons.

  
In this example we show a section of the map in detail. We've set up a series of lines using the vegetation terrain, and polygons using the surface terrain.  
We'll leave the vegetation terrain as before (except unchecking the polygon edge box), but set the surface terrain up to mix a yellow and light green - which will give an effect similar to oilseed rape.  

Our rendered image is reminiscent of an English field patchwork. For effect we've also added a couple of wind turbines.

This image is rendered at fractal level 4, to give better textures to the oilseed rape surfaces.

  
And here's the same landscape with the lighting conditions set towards dusk. Again rendered at fractal level 4.