Cameras
Cameras render scenes so that the user can view them. Every scene must have at least one camera. In fact, when a new scene is created, Unity creates a camera named Main Camera. As you'll see later in this book, a scene can have multiple cameras. In the Scene view, cameras are indicated with a white camera silhouette, as shown in the following screenshot:
Cameras are game objects and can be edited using transform tools as well as in the Inspector view. We can classify Unity cameras based on their projection. A perspective projection camera renders a scene based on the camera angle, as it exists in the scene.
The other project is orthographic. An orthographic perspective camera renders a scene uniformly without any perspective. This type of camera is commonly used for top-down games and is the default camera used in 2D and Unity's User Interface (UI) system.
When a camera is selected in the Hierarchy view, its frustum is visible in Scene view. A frustum is a geographic shape that looks like a pyramid that has had its top cut off. The top plane is parallel to its base, in other words, the near and far plane.
We'll use cameras in our game later in the book.
Note
There are additional user interface components to Unity that we did not cover. As we need them in the development of our game, they'll be introduced prior to use.