Every time you want to make a new Unity game, including coin collection games, you'll need to create New Project. Generally speaking, Unity uses the term Project to mean a Game. There are two main ways to make a new project, and it really doesn't matter which one you choose because both end up in the same place. If you're already in the Unity interface, looking at an existing scene or level, you can select File | New Project from the application menu. See Figure 1.2. It may ask if you want to save changes to the currently opened project and you should choose either Yes or No, depending on what you need. After selecting the New Project option, Unity leads you to the project creation wizard:

Figure 1.2: Creating a new project via the main menu

Alternatively, if you've just started Unity for the first time, you'll probably begin at the welcome dialog. See Figure 1.3. From here, you can access the new project creation wizard by choosing the NEW PROJECT button:

Figure 1.3: The Unity welcome screen

On reaching the NEW PROJECT creation wizard, Unity can generate a new project for you on the basis of some basic settings. Simply fill in the name of your project (such as CollectionGame), and select a folder on your computer to contain the project files that will be generated automatically. Finally, click on the 3D button to indicate that we're going to create a 3D game, as opposed to 2D, and then click on the Create project button to complete the project generation process. See Figure 1.4:

Figure 1.4: Creating a new project

Unity has now created a blank, new, and empty project. This represents the starting point for any game development project and is the place where development begins. The newly created project contains nothing initially: no meshes, textures, or any other Assets. You can confirm this by simply checking the Project panel area at the bottom of the editor interface. This panel displays the complete contents of the project folder, which corresponds to an actual folder on your local drive created earlier by the project wizard. This folder should be empty. See Figure 1.5. This panel will later be populated with more items, all of which we can use to build a game.

Figure 1.5: The Unity project panel docked at the bottom of the interface

Figure 1.6: Switching to the default interface layout

You can view the contents of your project folder directly via either Windows Explorer or Mac Finder, by right-clicking the mouse in the Project panel from the Unity Editor to reveal a context menu, and from there, choose the Show in Explorer (Windows) or Reveal in Finder (Mac) option. See Figure 1.7:

Figure 1.7: Displaying the project folder via the Project panel

Clicking on Show in Explorer displays the folder contents in the default system file browser. See Figure 1.8. This view is useful to inspect files, count them, or back them up. However, don't change the folder contents manually this way via Explorer or Finder. Specifically, don't move, rename, or delete files from here, because doing so can corrupt your Unity project irretrievably. Instead, delete and move files where needed within the Project panel in the Unity Editor. This way, Unity updates its metadata as appropriate, ensuring that your project continues to work properly.

Figure 1.8: Viewing the Project panel from the OS file browser

Assets are the raw materials for games—the building blocks from which they're made. Assets include meshes (or 3D models), such as characters, props, trees, houses, and more: textures, which are image files such as JPEGs and PNGs (these determine how the surface of a mesh should look); music and sound effects to enhance the realism and atmosphere of your game, and finally, scenes, which are 3D spaces or worlds where meshes, textures, sounds, and music live, exist, and work together holistically as part of a single system. Thus, games cannot exist without assets—they would otherwise look completely empty and lifeless. For this reason, we'll need assets to make the coin collection game we're working toward. After all, we'll need an environment to walk around and coins to collect!

Unity, however, is a game engine and not an asset creation program. This means that assets, such as characters and props, are typically made first by artists in external, third-party software. From here, they are exported and transferred ready-made to Unity, and Unity is responsible only for bringing these assets to life in a coherent game that can be played. Third-party asset creation programs include Blender (which is free of charge), Maya or 3DS Max to make 3D models, Photoshop or GIMP (which is free of charge) to create textures, and Audacity (which is free of cost) to generate audio. There are plenty of other options too. The details of these programs are beyond the scope of this book. In any case, Unity assumes that you already have assets ready to import to build a game. For the coin collection game, we'll use assets that ship with Unity. So let's import these to our project. To do this, select Assets | Import Package from the application menu. Then select Characters, ParticleSystems, Environment, and Prototyping. See Figure 1.9:

Figure 1.9: Importing assets via the Import Package menu

Each time you import a package from the menu, you'll be presented with an Import dialog. Simply leave all settings at their defaults, and click on Import. See Figure 1.10:

Figure 1.10: Choosing Assets to import

By default, Unity decompresses all files from the package (a library of assets) into the current project. After importing, lots of different assets and data will have been added to the Project, ready for use. These files are copies of the originals. So any changes made to the imported files will not affect or invalidate the originals, which Unity maintains internally. The files include models, sounds, textures, and more. These are listed in the Unity Editor from the Project panel. See the following screenshot:

Figure 1.11: Browsing imported assets from the Project panel

Figure 1.12: Downloading the Standard Assets package

The imported assets don't exist yet in our game. They don't appear on screen, and they won't do anything yet! Rather, they're simply added to the Project panel, which behaves as a library or repository of assets, from which we can pick and choose to build up a game. The assets imported thus far are built-in into Unity and we'll be continually using them in subsequent sections to make a functional coin collection game. To get more information about each asset, you can select the asset by clicking on it with the mouse, and asset-specific details will be shown on the right-hand side of the Unity Editor in the Inspector. The Inspector is a property sheet editor that appears on the right-hand side of the interface. It is context-sensitive and always changes to display properties for the selected object. See Figure 1.13.

Figure 1.13: The Inspector displays all the properties for the currently selected object

We've now created a Unity project and imported a large library of assets via the Unity Standard Asset package, including architectural meshes for walls, floors, ceilings, and stairs. This means that we're now ready to build our first level using these assets! Remember, in Unity, a scene means a level. The word scene and level can be used interchangeably here. They refer simply to a 3D space, that is, the space-time of the game world—the place where things exist. Since all games happen in space and time, we'll need a scene for the coin collection game. To create a new scene, select File | New Scene from the application menu, or press Ctrl + N on the keyboard. When you do this, a new and empty scene is created. You can see a visualization or preview of the scene via the Scene tab, which occupies the largest part of the Unity interface. See Figure 1.14.

Figure 1.14: The Scene tab displays a preview of a 3D world

Each new scene begins empty; well, almost empty. By default, each new scene begins with two objects. Specifically, a Light to illuminate any other objects that are added, and a Camera to display and render the contents of the scene from a specific vantage point. You can view a complete list of all the objects existing in the scene using the Hierarchy panel, which is docked to the left-hand side of the Unity interface. See Figure 1.15. This panel displays the name of every GameObject in the scene. In Unity, the word GameObject simply refers to a single, independent, and unique thing that lives within the scene, whether visible or not: meshes, lights, cameras, props, and more. Thus, the Hierarchy panel tells us about everything in the Scene.

Figure 1.15: The Hierarchy panel

Next, let's add a floor to the scene. After all, the player needs something to stand on! We could build a floor mesh from scratch using third-party modeling software such as Maya, 3DS Max, or Blender. However, the Unity Standard Asset package, which was imported earlier, contains floor meshes that we can use. This is very convenient. These meshes are part of the Prototyping package. To access them via the Project panel, open the Standard Assets folder by double-clicking it, and then access the Prototyping | Prefabs folder. From here, you can select objects and preview them from the Inspector. See Figure 1.16.

Figure 1.16: The Standard Assets/Prototyping package contains many meshes for quick scene building

The mesh named FloorPrototype64x01x64 (as shown in Figure 1.16) is suitable as a floor. To add this mesh to the scene, simply drag and drop the object from the Project panel to the Scene view and then release the mouse. See Figure 1.17. When you do this, notice how the Scene view changes to display the newly added mesh within the 3D space, and the mesh name also appears as a listing in the Hierarchy panel:

Figure 1.17: Dragging and dropping mesh assets from the Project panel to the Scene view will add them to the scene

The floor mesh asset from the Project panel has now been instantiated as a GameObject in the scene. This means that a copy or clone of the mesh asset, based on the original in the Project panel, has been added to the scene as a separate GameObject. The Instance (or GameObject) of the floor in the scene still depends on the floor asset in the Project panel. However, the asset does not depend on the instance. This means that by deleting the floor in the scene, you will not delete the asset. However, if you delete the asset, you will invalidate the GameObject. You can also create more floors in Scene if you want by dragging and dropping the floor asset many times from the Project panel to the Scene view. Each time, a new instance of the floor is created in the Scene as a separate and unique GameObject, although all the added instances will still depend on the single floor asset in the Project panel. See Figure 1.18:

Figure 1.18: Adding multiple instances of the floor mesh to the scene

We don't actually need the duplicate floor pieces, however. So let's delete them. Just click on the duplicates in the Scene view and then press Delete on the keyboard to remove them. Remember, you can also select and delete objects by clicking on their name in the Hierarchy panel and pressing Delete. Either way, this leaves us with a single floor piece and a solid start to building our scene. One remaining problem, though, concerns the floor and its name. By looking carefully in the Hierarchy panel, we can see that the floor name is FloorPrototype64x01x64. This name is long, obtuse, and unwieldy. We should change it to something more manageable and meaningful. This is not technically essential but is good practice to keep our work clean and organized. There are many ways to rename an object. One way is to first select it and then enter a new name in the name field in the Object Inspector. I'll rename it WorldFloor. See Figure 1.19:

Figure 1.19: Renaming the floor mesh

A scene with a floor mesh has been established, but this alone is uninteresting. We need to add more, such as buildings, stairs, columns, and perhaps more floor pieces. Otherwise, there would be no world for the player to explore. Before building on what we've got, however, let's make sure that the existing floor piece is centered at the world origin. Every point and location within a scene is uniquely identified by a coordinate, measured as an (X, Y, Z) offset from the world center (origin). The current position for the selected object is always visible from the Object Inspector. In fact, the Position, Rotation, and Scale of an object are grouped together under a category (component) called Transform. Position indicates how far an object should be moved in three axes from the world center. Rotation indicates how much an object should be turned or rotated around its central axes. Scale indicates how much an object should be shrunk or expanded to smaller or larger sizes. A default Scale of one means that an object should appear at normal size, two means twice the size, and 0.5 means half the size, and so on. Together, the Position, Rotation and Scale of an object constitute its transformation. To change the position of the selected object, you can simply type new values in the X, Y, and Z fields for Position. To move an object to the world center, simply enter (0, 0, and 0), as shown in Figure 1.20:

Figure 1.20: Centering an object to the world origin

Setting the position of an object, as we've done here, by typing numerical values is acceptable and appropriate for the specifying of exact positions. However, it's often more intuitive to move objects using mouse-based controls. To do this, let's add a second floor piece and position it away from the first instance. Drag and drop a floor piece from the Project panel in Scene to create a second floor GameObject. Then click on the new floor piece to select it and switch to the Translate tool. To do this, press W on the keyboard or click on the translate tool icon from the toolbar at the top of the editor interface. The translate tool allows you to reposition objects in Scene. See Figure 1.21:

Figure 1.21: Accessing the translate tool

When the translate tool is active and an object is selected, a Gizmo appears centered on the object (three colored axes visible in the Scene tab). The translate Gizmo appears as three colored perpendicular axes: red, green, and blue corresponding to X, Y, and Z respectively. To move an object, hover your cursor over one of the three axes (or planes between axes), and then click and hold the mouse while moving it to slide the object in that direction. You can repeat this process as often as needed to ensure that your objects are positioned where you need them to be. Use the translate tool to move the second floor piece away from the first. See Figure 1.22:

Figure 1.22: Translate an object using the translate Gizmo

You can also rotate and scale objects using the mouse, as with translate. Press E to access the rotate tool or R to access the scale tool, or you can activate these tools using their respective toolbar icons from the top of the editor. When these tools are activated, a Gizmo appears centered on the object, and you can click and drag the mouse over each specific axis to rotate or scale objects as needed. See Figure 1.23:

Figure 1.23: Accessing the rotate and scale tools

Being able to translate, rotate, and scale objects quickly through mouse and keyboard combinations is very important when working in Unity. For this reason, make using the keyboard shortcuts a habit as opposed to accessing the tools continually from the toolbar. However, in addition to moving, rotating, and scaling objects, you'll frequently need to move around yourself in the Scene view in order to see the world from different positions, angles, and perspectives. This means that you'll frequently need to reposition the scene preview camera in the world. You'll want to zoom in and zoom out of the world to get a better view of objects and change your viewing angle to see how objects align and fit together properly. To do this, you'll need to make extensive use of both the keyboard and mouse together.

To zoom closer or further from the object you're looking at, simply scroll the mouse wheel up or down—up zooms in and down zooms out. See Figure 1.24:

Figure 1.24: Zooming in and out

To pan the Scene view left or right, or up or down, hold down the middle mouse button while moving the mouse in the appropriate direction. Alternatively, you can access the pan tool from the application toolbar (or press Q on the keyboard) and then simply click and drag in the Scene view while the tool is active. Pan does not zoom in or out; it simply slides the camera left and right, or up and down.

Figure 1.25: Accessing the Pan tool

Sometimes, while building levels, you'll lose sight entirely of the object that you need. For example, your viewport camera could be focusing on a completely different place from the object you really want to click or see. In this case, you'll often want to shift the viewport camera automatically in order to focus on that specific object. Specifically, you'll want to reposition and rotate the viewport as necessary to bring a desired object to the center of the view. To do this automatically, select the object to focus on (or frame) by clicking on its name from the Hierarchy panel. Then, press the F key on the keyboard. Alternatively, you can double-click its name in the Hierarchy panel. See Figure 1.26:

Figure 1.26: Framing a selected object

After framing an object, you'll often want to rotate around it in order to quickly and easily view it from all important angles. To achieve this, hold down the Alt key on the keyboard while clicking and dragging the mouse to rotate the view. See Figure 1.27:

Figure 1.27: Rotating around the framed object

Lastly, it's helpful to navigate a level in the Scene view using first-person controls, that is, controls that mimic how first-person games are played. This helps you experience the scene at a more personal and immersive level. To do this, hold down the right mouse button and (with the button depressed) use the WASD keys on the keyboard to control forward, backward, and strafing movement. Movement of the mouse controls head orientation. You can also hold down the Shift key while moving to increase movement speed. See Figure 1.28:

Figure 1.28: Using first-person controls

The great thing about learning the versatile transformation and navigation controls is that, on understanding them, you can move and orient practically any object in any way, and you can move and view the world from almost any position and angle. Being able to do this is critically important to build quality levels quickly. All of these controls, along with some others that we'll soon see, will be used frequently throughout this book to create scenes and work in Unity generally.

Now that we've seen how to transform objects and navigate the scene viewport successfully, let's proceed to complete our first level for the coin collection game. Let's separate the two floor meshes apart in space, leaving a gap between them that we'll fix by creating a bridge, which the player will be able to cross, moving between the floor spaces like islands. We can use the translate tool (W) to move objects around. See Figure 1.29:

Figure 1.29: Separating the floor meshes into islands

Next, we'll add some props and obstacles to the scene. Drag and drop some house objects onto the floor. The house object (HousePrototype16x16x24) is found in the Assets | Standard Assets | Prototyping | Prefabs folder. See Figure 1.30:

Figure 1.30: Adding house props to the scene

On dragging and dropping the house in the scene, it may align to the floor nicely with the bottom against the floor, or it may not align like that. If it does, that's splendid and great luck! However, we shouldn't rely on luck every time because we're professional game developers! Thankfully, we can make any two mesh objects align easily in Unity using vertex snapping. This feature works by forcing two objects into positional alignment within the scene by overlapping their vertices at a specific and common point.

For example, consider Figure 1.31. Here, a house object hovers awkwardly above the floor and we naturally want it to align level with the floor and perhaps over to the floor corner. To achieve this, start by selecting the house object (click on it or select it from the Hierarchy panel). The object to be selected is the one that should move to align and not the destination (which is the floor), which should remain in place.

Figure 1.31: Misaligned objects can be snapped into place with Vertex Snapping

Next, activate the translate tool (W) and hold down the V key for vertex snapping. With V held down, move the cursor around and see how the Gizmo cursor sticks to the nearest vertex of the selected mesh. See Figure 1.32. Unity is asking you to pick a source vertex for the snapping:

Figure 1.32: Hold down V to activate Vertex Snapping

With V held down, move the cursor to the bottom corner of the house, and then click and drag from the corner to the floor mesh corner. The house will then snap align to the floor, corner to corner. When aligned this way, it release the V key, and the two meshes get aligned exactly at the vertices. See Figure 1.33:

Figure 1.33: Align two meshes by vertices

Now you can assemble a complete scene using the mesh assets included in the Prototyping package. Drag and drop props in the scene, and using translate, rotate, and scale, you can reposition, realign, and rotate these objects; using vertex snapping, you can align them wherever you need. Give this some practice. See Figure 1.34 for the scene arrangement that I made using only these tools and assets:

Figure 1.34: Building a complete level