How to do it...

To begin:

1. Open up the Package Manager by going to Window | Package Manager (or by pressing Ctrl + 9):

1. From the list view, click on the All button to display a list of all of the possible packages that are there. Once the list populates with all of the choices, select the Post-processing option:

1. From there, at the top right of the menu, click on the Install 2.0.7-preview button. You may need to wait for a while for it to complete downloading the content. Once it's completed, you should be brought back to the In Project selection and now you'll see Post-processing added to the list:

1. Close out of the Packages tab and go back to the Scene window to see the level. Then, from the Hierarchy window, we want to select the object that has our Camera component attached to it, as the Post Processing Stack needs to know which screen we want to modify. If you are using your own project, you may select the MainCamera object that comes with the default Unity scene, but the example project that is being used has the Camera located as a child of the FPSController object. To select it, click on the arrow next to the name to extend the object's children and then select the FirstPersonCharacter object:

This object has the Camera component on it, which is in charge of drawing what it sees to the Game tab when the game starts.

You can double-click on a game object in the Hierarchy tab to zoom the camera from the Scene tab to its location. This makes it very easy to find things, even in a large game level.

1. With the object selected and our Camera component attached to it, next we need to add the Post-processing Behavior component to the object by going into Component | Rendering | Post-process Layer:

1. Once added, from the Inspector tab, scroll down to the Post Process Layer (Script) component and, under Layer, change the dropdown to PostProcessing.
2.   This tells the component which objects we want to draw on the screen. When setting this, an object must have its Layer property set to PostProcessing in order to be seen. 

1. To create a Post Process Volume, go to the menu and select GameObject | 3D Object | Post Process Volume. From there, go to the Inspector tab and change the Layer property to PostProcessing. Finally, to make it easier to work with, change the Position to 0, 0, 0 and under the Post Process Volume component, check the Is Global property:

Notice that there is a Profile property to the volume. This property will contain information about how we wish to modify the screen. By checking Is Global, we are saying that this information should always be drawn on an object. By unchecking it, the effects will only be visible from a certain distance from where the volume is placed. Depending on the game, this could allow you to drastically modify how the game appears in certain areas, but we care only about getting the visual effect at this point.