Unreal Development Kit Game Design Cookbook: Over 100 recipes to accelerate the process of learning game design with UDK book and ebook.

In Chapter 1, Heads Up, we ripped through getting started with UDK, establishing a scene, using the Content Browser to build and package a level or map, albeit in a bare bones fashion. Now let's look at actual environment features. To begin developing a scene, we need a geometry modeling tool (BSP), a method of terrain editing (for which UDK now has two). Also, while covering these basics, it's a good point to introduce other content generation tools that UDK provides, such as the scattering tool Foliage, and the particle creation tool Cascade.

BSP stands for Binary Space Partition. BSP allows you to quickly create and lay out surfaces such as floors, walls, and ceilings which are lined up with each other without having to worry about using any other software. BSP helps you in the design stage, and generally geometry made with BSP can later be replaced by more efficient, more detailed StaticMesh assets. But besides being a modeling tool, BSP can be used to do a lot more, like serve as triggers, lighting volumes, and collision. We'll look at how to generate BSP and how to convert it to a StaticMesh and to a Volume.

You may have noticed there are more BSP brush creation options than we've discussed. A useful one is to create a hollow BSP with a preset thickness. This allows us to quickly create interiors.

Once you have applied a Material to a BSP surface, you may want to resize or shift it on the selected surface. This can be done directly in Texture Alignment Mode (Shift + F4) which is slightly clumsy, or through the menu View/Surface Properties Editor (F5).

The BSP brush can be used to generate volumes that cover functionality like defining a spatial zone for something to happen (or not happen) inside. In later chapters we'll be using all kinds of volumes. For now let's choose a simple one, a PostProcess Volume. This volume type effects the coloration and focus of the image seen by the camera. The use of a volume provides a boundary for the effect.

StaticMesh actors are the meshed geometry in the scene used by designers to represent fixed environment components. A large library of these comes with the content provided by Epic Games in UDK. In this recipe we'll look at ways to bring that content into the scene, shift it around and adjust it, and make sure that lining it up with other content is no problem. We'll also look at converting a StaticMesh for other uses. In the previous recipe we set up a small scene just using BSP elements. This time we'll only use meshes from the Browser.

When you convert BSP to a StaticMesh, and when you import a new model from an external source, the mesh will have no collision calculated. UDK provides an easy way to automatically generate collision geometry for imported StaticMesh assets. Collision geometry can be calculated from the actual mesh, but that is seldom efficient. It is better to use a proxy mesh with far fewer polygons, encasing the visible model. Instead of bumping into the visible model while playing, you'd instead be bumping into the low res collision model linked to it. Without collision you'd run right through the model, though that may be desirable for some models, such as grass, flowers, the canopies of trees, and things that would otherwise be troublesome to snag against when moving.

This recipe covers the basics of adding a Terrain to your scene, and shows how StaticMesh actors can be distributed over its surface. We also look at brushes that can touch up the HeightMap to support meshes on the deco layer, and then improve the look of the terrain's surface by adding decals. We don't cover everything involved in terrain editing, since you can probably make your own inroads after doing this example. Also, the Terrain tool is somewhat overshadowed by the newer Landscape tool, and its accompanying addition Foliage which takes over the role of Deco Layers. Still, both tools are powerful. A terrain can even be converted into a landscape later on.

This recipe covers the basics of making a Landscape, which is a newer alternative to using the Terrain tool. It features a more painterly tool set, and can also import Heightmaps from software such as Vue or Terragen. Heightmaps are black and white textures where light tones influence a surface to push it upwards, and darker tones effect it less. Our goals will be to model a simple Landscape asset, and paint texture layers on it. Afterward, we'll scatter trees and rocks across it using the Foliage tool (which isn't limited to foliage).

Foliage Mode extends the Landscape tools, and sits alongside Landscape Mode in the editor. In this recipe we'll scatter rock meshes on a Landscape surface, since the Foliage tool, while great for making forests and grass, is not limited to just that.

The goal of this chapter has been to overview a broad spectrum of the UDK content generation tools, so now we jump to a new area, particle effects. In the first chapter we created an asset which was an empty particle system, aiming to show how its package would be created and saved, but having left it at that it would be good to flesh it out. So we'll look a little deeper into Cascade and create a steamy plume which can be applied in a scene as a set dressing. This recipe is a quick guide to the essentials. We will deal with advanced Cascade challenges in Chapter 7, Hi, I'm Eye Candy!