The Scene window
The Scene window is where you can position your Game Objects and move them around. This window has various controls to change its level of detail. Use these controls to toggle lighting on and off, and to display the window contents with textures, wireframes, or a combination of both. You can use the colorful gizmo in the top-right corner to constrain the view to the X, Y, and Z axes to view the top and sides of your scene. Click on the white box in the middle to return to perspective view. This window also features a search field. Try clicking on the gizmo's green Y cone to view the AngryBots Demo from above, and then type rock into the search field. Every object with "rock" in its name lights up, while the rest of the scene fades to grayscale. Press the tiny x button to clear the search field.
The Game window
The Game window shows you what your players will see. When you click on the Play button to test your game (as you just did with the AngryBots Demo) the results of your efforts play out in this window. Toggle the Maximize on Play button to test your game in full-screen mode.
The Hierarchy
The Hierarchy panel lists all of the Game Objects in your Scene. Game Objects—cameras, lights, models, and prefabs—are the things that make up your game. They can be "tangible" things like the airlock doors and the cannisters in the AngryBots Demo. They can also include intangible things, which only you as the game developer get to see and play with, such as the cameras, the lights, and colliders, which are special invisible shapes that tell the game engine when two Game Objects are touching.
The AngryBots Demo Hierarchy contains Game Objects for the cannisters, the tables, the airlocks and the computer terminals, to name a few. It also lists the Player, a very complicated Game Object that controls how the hero moves and collides with his environment. The player character has a camera following him. That camera is our eye into the game world. The demo lists a collection called Environment (sounds)—a series of Game Objects that determine what the player hears when he walks through different parts of the level (such as torrential rain outside, and the droning equipment hum when he moves indoors). So, Game Objects can include touchy-feely "physical" objects such as cannisters and airlocks, as well as behind-the-scenes intangible things such as lights, cameras, and actions (scripts).
Click on a Game Object in the Hierarchy panel, and then hover your mouse over the Scene window. Press the F key on your keyboard, and the Scene window will automatically pan and zoom directly to that object. Alternatively, you can go to Edit | Frame Selected, which can be more reliable than using the keyboard shortcut. (I like to think of the F as standing for Focus to help me remember what this shortcut does.)
The Project panel
The Project panel lists all of the elements that you'll use to create Game Objects in your project. For example, look for the mech_bot in the Objects/Enemies folder. The AngryBots Demo EnemyMech Game Object is made up of a series of meshes that represent the mech's shape, a material to depict its "skin" or coloring, and an animation to describe its movement. All of these types of goodies are listed in the Project panel.
The Project panel displays the contents of a special folder on your computer's operating system called Assets. Unity automatically creates the Assets folder for you when you create a new project. If you drag a compatible file, like a 3D model, a sound effect, or an image into the Project panel, Unity copies it to the Assets folder behind the scenes, and displays it in the Project panel.
Tip
Don't mess with the Assets folder!
Unity stores metadata about the folder, and by moving stuff around or deleting things through your operating system, you may break your project. If you need to make changes, make them right inside Unity in the Project panel.
The Inspector
The Inspector is a context-sensitive panel, which means that it changes depending on what you select elsewhere in Unity. This is where you can adjust the position, rotation, and scale of Game Objects listed in the Hierarchy panel. The Inspector can also display controls to configure components that add functionality to Game Objects. Between the three main panels in Unity (Hierarchy, Project, and Inspector), the Inspector is where you'll likely spend most of your time because that's where you'll be tweaking and fiddling with every aspect of the elements that comprise your game projects.
The preceding screenshot of the Inspector shows the components attached to the Player Game Object in the AngryBots Demo: a number of scripts (including Free Movement Motor and Player Move Controller), a Rigidbody component, a Capsule Collider, and others. To see the same content on your computer, click to open the Player Game Object in the Hierarchy panel.
Heads up?
Let's use the Inspector panel to make a quick change to the orientation of the character. We'll begin the demo with the hero standing on his head (which is a sure-fire way to make those bots even angrier, by the way).
We can use the Inspector panel to change the rotation of the player. Follow these steps:
- In the Hierarchy panel, click to select the Player Game Object.
- Click on the Rotate button, which looks like two arrows sniffing each others' behinds.
A globe appears around the bottom of the Player Game Object. The red X-axis rotator handle encircles the player's body. Clicking and dragging it rotates the player model as if he were standing in a very dodgy canoe. The blue Z-axis rotator handle rotates the player as if there was an invisible pin running through his ankles. If we click-and-drag that handle, the player rotates to either fall flat on his face, or flat on his back, like he's got space sickness. And the green Y-axis rotator handle runs around the player like a hula hoop.
Dragging this handle around makes the player spin to face different directions. The Player Game Object can get pretty hairy; in order to isolate the rotation controls, type player into the Scene window's search field to exclude all other Game Objects. (Remember that you can bring the selected Game Object into view by pressing the F key when your mouse cursor is within the Scene view.)
- You can click-and-drag the red X-axis arrow to turn the player upside down, but a better method is to change the X-axis rotation in the Inspector panel. Expand the gray arrow next to Transform in the Inspector panel if it's not already open, and change the X value under Rotation to 180. The player flips upside down.
- Now, when you click on Play to test the game, the player will break-dance his way around the AngryBots Demo, electric boogaloo-style. The robots are freaking out, thinking "ERROR! DOES NOT COMPUTE!" Way to keep them on their mechanical toes.
Layers and layout dropdowns
Above the Inspector panel, you'll see the Layers and Layout dropdowns. Game Objects can be grouped into layers, somewhat like in Photoshop or Flash. Unity stores a few commonly used layouts in the Layout dropdown (mine is set to the "2 by 3" configuration). You can also save and load your own custom layouts.
Playback controls
These three buttons help you test your game and control playback. As you've seen, the Play button starts and stops your game. The Pause button works as expected—it pauses your game so that you can make changes to it on the fly. The third button is a Step-Through control; use it to advance frame-by-frame through your game so that you can more tightly control what's going on.
Tip
Changes you make while testing don't stick!
One of the more surprising features of Unity is that you can make changes to Game Objects and variables on the fly while you're testing your game. But it's important to know that the changes you make during testing will not "stick". Once you stop testing your game, the changes that you made during testing will revert to the state they were in before you clicked on the Play button. It's disheartening to make a number of changes to your game, only to realize that the Play button was on the entire time, and your changes will be lost. One way to avoid this problem is to toggle the Maximize on Play button in the Game window so that you'll be more aware of when you're testing and when you're not.
Scene controls
At the top-left of your screen, you'll see four controls that help you move around your Scene, and position Game Objects within it. These controls are mapped to the Q, W, E, and R keys on your keyboard. From left to right, they are:
- The Hand tool (Q): Use it to click-and-drag around your scene. Hold down the Alt key on your keyboard to rotate the view. Hold down the Ctrl key (Windows) or the Command/control key (Apple) to zoom in and out. Your mouse wheel will also zoom the scene. Hold down the Shift key to pan, zoom, and rotate in larger increments to speed things up. This is a way for you to navigate around the game world. It doesn't actually impact the way the player sees the game. To modify the Game view, you need to use the Move or Rotate tools to modify the Camera position.
- The Move tool (W): This tool lets you move the Game Objects around your scene. You can either drag the object(s) around by the X, or Y, or Z-axis handles, or by the square in the center for freeform movement. Holding down the Ctrl key or Command key (Apple) will snap movement to set grid increments. Hold down Shift at the same time to snap objects to the "floor".
- Rotate tool (E): Use it to spin your objects around using a neat spherical gizmo. The red, green, and blue lines map to the X, Y, and Z axes.
- Scale tool (R): This tool works much the same as the Move and Rotate tools. Use it to make your Game Objects larger or smaller. Dragging an X, Y, or Z handle will non-uniformly scale (squash and stretch) the object, while dragging the gray cube in the center will uniformly scale it.