Chapter 6. Terrain

Unreal Engine 3 supports a flexible terrain system that provides a wide variety of visual styles and uses. Many different landscapes can be realized and various themes can be achieved utilizing a heightmap based system that can visually depict hills, valleys, mountains, rivers, roads, and more. It can also depict a multi-layer terrain material system that supports real-world texture files such as dirt, rock, sand, and mud.

A multi-layer decoration system provides additional flexibility and realism by rendering foliage such as grass, weeds, bushes, flowers, and even small rocks and debris.

Terrain is typically created using one of the two techniques: hand-painting directly on the terrain mesh to create the hills and valleys, or importing externally created terrain height maps. Additionally, height map information can be acquired from Digital Elevation Model (DEM) information. Material layers that represent dirt, grass, and rocks can be created using terrain alpha maps that...

Time for action – your first terrain

Before you add a terrain to a level, be sure to have saved the level at least once, as the terrain will attempt to save itself within the level, for which the level has to exist in the first place.

1. Open the generic browser. If it isn't already open, go to the Actors tab, expand the Uncategorized section and select the actor Terrain, as shown in the following screenshot:

   

2. In the viewport, hold down a on your keyboard, and click a surface in your level to add the Terrain actor at that location. Your terrain should show up as shown in the following screenshot; tiny, and with a default texture applied.

3. Let's expand it. New for Unreal Engine 3 is the ability to expand a terrain whenever you want. You are no longer restricted to the original size as you were in Unreal Engine 2. Double-click the terrain in the viewport to have its properties pop up. You should preferably also set the viewport to wireframe to get a better view on what's going on:

   

   NumPatches X and...

Time for action – applying materials

Let's add textures/materials to the terrain.

1. Switch the viewport back to a textured view and go to the generic browser. Find a material that you like, select it in the generic browser, and return to the Terrain Editing Mode window.

2. In the Terrain Editing Mode window, right-click the big empty space at the bottom, below where it says Height Map, pick New Layer from material (auto-create), and enter a name.

3. Select another material in the generic browser, and do this one more time so you have two layers as shown in the next screenshot. If it asks for a package and layer name, as some versions do (UT3), ensure that your package name is the same as your level name, to embed the material information inside the level itself. UDK will ask for a name twice: one for TerrainLayerSetup and one for Terrain Material. Enter two different names for the two, but the same package name. If your level is named Layouttest754, your package too should be named the same. The layer...

Time for action – light mapping

1. Unlike Unreal Engine 2, terrain is light mapped now. However, if the quality of the light map is not satisfactory enough, it is possible to bump up its quality. To do so, open up the properties of the terrain and expand the Lighting section. Enable bIsOverridingLightResolution, and enter a higher value under StaticLightingResolution.

   Note

   This can have quite a performance impact; so again, use it wisely.

   

What just happened?

We have assigned a light map to the terrain so when static meshes are introduced to our map and light hits the meshes, we will get dynamic shadowing, giving a more atmospheric approach to our map.

Have a go hero – foliage layers

Foliage layers are embedded into regular terrain material layers, and are thus linked to the material. Paint another material over the one that contains the foliage layer, and the foliage layer too will disappear.

1. In the generic browser, browse to the terrain material of the layer of choice, usually found within the Mylevel...

Summary

We learned a lot in this chapter about the following:

• Creating a terrain in our map

• Applying materials to our terrain

• Adding a light map to our terrain

We have learnt how to build a basic terrain, how to apply materials to that terrain, making it more atmospheric and giving it character. We also know how to add light mapping to our terrain, which give us dynamic shadowing when static meshes are introduced to our map. In the next chapter we will start adding items and look into bot placement.