Our game environment should be dark, creepy, and suspenseful. However, every new Unity scene is created with a default, procedural skybox representing a cheery daytime exterior; this needs to be changed. A skybox is ultimately a cube with a flipped normal that surround and encompass the environment. Its faces contain an environment texture which, when mapped correctly, appears seamlessly across the model, creating the look of a vast skyline surrounding the scene. The primary purpose of our skybox should be to set a base and ambient lighting. The most appropriate skybox for our usage, then, is a night skybox or, at least, a dark, stormy (and perhaps slightly alien) skybox. There are many ways to create a skybox in Unity. One method is to create a cube-map texture (six separate textures) inside the image-editing software that maps to the faces of...

Now the fun begins, though it's logistically challenging: the process of level building. Our aim is to build a fun and interesting level, but this must be balanced against many factors, including level size, ease of navigation, variety, and more. Creating a level is challenging because misplaced or poorly designed elements stand out for their failings. They break the player's experience. Decisions about architecture and where to include straight sections, turns, jumps, ledges, props, and doors collectively influence the atmosphere and mood of a level. Here, we'll focus on the modular building method, piecing together an expansive level from reusable pieces, exploring reasons and justifications for our choices along the way. However, let's first see the modular set in its entirety, that is, the complete collection of...

Let's start the level construction process. There are many ways to begin here, but it's a good idea from the outset to develop with a clean workflow in mind. By clean, I mean an organized, structured, and easy-to-maintain workflow, one that remains maintainable for projects of many scales. First, delete any and all objects in the new scene, and then create a single empty GameObject named root by navigating to GameObject | Create Empty from the application menu. This object will be the topmost object in the hierarchy, from which everything else will be a child directly or indirectly:

Next, create a new child object named env, which will contain all environment pieces. Ensure that both the root and env objects are positioned at the world origin at (0,0,0). I typically position the world floor...

Don't underestimate the design challenges faced when building a level. Arranging mesh modules meaningfully and constructing a layout that encourages exploration and invites interest is challenging. Is a corridor too long or too bendy? Is a walkway too narrow or too wide? Should there be a prop (such as a chair or a desk) in the corner of a room? These types of question, and others, matter! They're not the kinds of thing that should be settled just by flipping a coin. Consider the following design tips and tricks, which are some guiding principles intended to help you build more interesting levels more quickly and easily.

Always remember the player objective when...

Reaching this far, you've now made a complete scene in terms of meshes representing the first level, composed of modular environment pieces (corridor sections). Presently, the level features no lighting, navigation meshes, music or audio, and Occlusion Data, but we'll add these soon. Let's start with lighting. In Unity, there are three main lighting types or systems, which exist on a spectrum:

• Baked lighting
• Real-time lighting
• Precomputed global illumination

These are discussed in further detail here.

Baked lighting is the optimal lighting method, but it can only be used under specific circumstances. With baked lighting, all lighting data (highlights, shadows, and...

To start baking scene lighting, we'll first need to activate Lightmap UVs for the environment meshes and then position some lights in the scene where appropriate. To activate Lightmap UVs, select all environment meshes in the Project panel and enable Generate Lightmap UV from the object Inspector. Then, click on Apply. This method is useful for generating a second UV channel when one doesn't already exist. This defines how lighting is baked to the lightmap texture. Unity applies an autounwrap projection using settings from the Advanced roll out. If, by contrast, your own meshes already have a custom, second channel, and you can use this channel instead for Lightmap UVs simply by disabling Generate Lightmap UVs:

Our scene now features marked static objects, complete with Lightmap UVs, and is ready for lightmapping. The default settings for all Unity scenes and projects is not compatible with a full lightmap setup as we require, and so we must access the lighting settings. To do this, display the Lighting window by navigating to Window | Lighting | Settings from the application menu. Once opened, dock the free-floating window into the object Inspector as a separate tab. This is convenient because we can view the lighting settings and inspect the Scene viewport side by side:

First, let's disable all precomputed GI settings by removing the check mark from the Realtime Global Illumination checkbox in the Realtime Lighting rollout. This completely deactivates real-time GI for the scene. In addition, specify the night...

Having now established a resolution and Lightmap Size, we should specify baking details to improve the quality and appearance of our lightmaps. To do this, enable Ambient Occlusion and tweak the Max Distance field until you get the volumetric effect desired. This requires rebaking. Ambient Occlusion is sometimes called Contact Shadows, because it generates shadows where two or more solid bodies meet, such as the floor meeting the wall, or crevices and cracks. This creates a volume effect, enhancing the 3D feel of a scene:

In addition, enable Final Gather. Set the Ray Count to 256. Final Gather reduces noise and improves the quality of lightmapping. Higher values result in smooth, higher quality output at the expense of the calculation time:

Finally, you can increase the resolution of specific objects...

The lightmap setup works well for the scene, but applies only to static objects, such as walls, floors, ceilings, and props. Animated and movable objects, such as NPCs, will continue to be illuminated by expensive dynamic lights, in contrast, unless additional steps are taken; let's take those now using Light Probes. They are special sampling objects, that should be positioned strategically around the scene to record an average of light color and intensity at that location. When multiple Light Probes exist, movable objects such as characters are illuminated by interpolated values taken from the nearest probes. Light Probes, therefore, record color and intensity, but they do not cast shadows. To get started with Light Probes, create a new game object to act as the parent of all probes. Navigate to GameObject | Create Empty from the application menu, and name this...

This section takes time out to explore lighting issues and problems that sometimes arise and common methods to solve them. The issues listed here may not arise for the Dead Keys project specifically, but it's likely that you'll encounter them somewhere, on some projects. Consequently, it's good to know how the issues are solved, or at least avoided. This section takes a question and answer format:

• Scene lighting appears wrong when opening a scene in the editor: This happens when Auto Generate is enabled from the Lighting window. As the scene is opened, lighting is rebaked. This may take time or may fail entirely for various reasons. The result is that scene lighting may not appear correct instantly when a scene is opened. You can resolve this by disabling auto generate from the Lighting window and then saving the scene to confirm the change. The next...

Now, it's time to explore NPC intelligence and, specifically, path finding. We'll need our NPC zombies to move around the scene intelligently, that is, to move without bumping into walls, floors, doors, and other obstacles, and without taking the most complex routes to nearby destinations. Our zombies must cleverly navigate their way around the environment, whatever its arrangement, finding their way toward the player to engage in combat, as though they really had brains! To achieve this, a navigation mesh is required. This is an invisible mesh asset, generated by Unity, to approximate the scene floor for both exterior and interior environments. More accurately, it represents the total walkable floor of the scene--the area over which NPCs may maneuver to travel from point to point. To access the navigation mesh features, click on Window | Navigation from...

Unity imposes no official limits on the size of your scene, and there's no established convention or industry-standard making recommendations about scene size. This is a decision largely in your hands, but there will certainly be a limit in a practical sense. The complexity of meshes, materials, and special effects combined with the number of meshes and their spread determines just how computationally expensive a scene is when presented to a camera with a specific frustum and field of view. Unity tries to make scene rendering easier on the computer by applying Frustum Culling automatically, that is, it silently deactivates (culls) objects outside the viewing volume (frustum) of the camera. As objects leave the frustum, Unity ceases to render them, and as they enter the volume, Unity starts rendering them. This optimization works well in many cases, for objects...

The camera object is, in many ways, the most important in any scene, because without the presence of at least one camera, the scene can't be rendered at all. Dead Keys will eventually feature multiple cameras, each with a dedicated purpose. However, let's focus on the main camera, that is, the player perspective in the scene now. For first person games, you can create a camera easily by dragging and dropping a First Person Controller from the Project panel into the scene, from the Characters asset package. However, for Dead Keys, we don't need that; our camera path is fixed as it moves through the level and the user doesn't need free-look controls with the mouse or W A S D keys. Consequently, we'll create a custom camera from the ground upwards.

Let's start by creating a camera object by navigating to GameObject | Camera from...

Particle systems are great for creating effects such as rain, snow, steam, sparkles, hordes of birds, footprints, armies of ants, and more. Unity ships with preconfigured particle systems ready to use, and it lets you create your own from scratch. Here, we'll use some premade systems that can be added easily to the scene, for drama and tension. To access the premade systems, import the ParticleSystem package into the project. Choose Assets | Import Package | ParticleSystems from the application menu if you've not imported the package already. From the Import dialog that appears, accept the default settings and click on the Import button:

Once imported, you can access all premade particle systems via the Project panel, through the Standard Assets | ParticleSystems | Prefabs folder:

For...

To complete basic level configuration and structure, let's add music, specifically, the main background music that should play continuously throughout the level. In the last chapter, we imported audio assets, both music and sound effects, and configured these optimally. As discussed earlier, it is most important that music is configured for Streaming as the Load Type, and the Compression Format should be set to Vorbis. This ensures that Unity doesn't load the complete track into memory as it would do with sound and audio. Loading complete music tracks will be performance prohibitive, especially for mobile devices and legacy hardware:

In addition to importing music assets, let's create an Audio Mixer asset. This is optional in theory, as Unity can play audio without a mixer. However, mixers give you more control over different...

Congratulations! You've now created the first level of Dead Keys. Of course, more will be added, but let's first focus on creating one functional level, whose behaviors may be easily recycled to produce more levels, as needed. This chapter focused on many level design issues, both practical and theoretical. Specifically, we explored level design tips and tricks--methods for producing levels more simply and conveniently. In addition, we examined the modular building technique, alongside more advanced tools such as lightmapping, navigation meshes, and Occlusion Culling. In the next chapter, we'll examine how to take the first person camera and build player functionality using animation and scripting.