An effect you can very commonly see in photography is objects that are very close to or very far away from the point of view. Therefore, appearing fuzzy and blurred while the middle portion of the image appears focused and sharp, emphasizing an object of interest in the scene. This focused part of the scene is referred to as 'depth of field'.
In this recipe you will learn how to mimic this cinematic effect in a post-processing filter. This will help you to emphasize the visual depth of a scene and focus a point of interest while blurring the background and foreground.
Set up the project structure found in Setting up the game structure, add a directory called shaders inside the project directory, make sure it is in the engine's search path and you're ready to go!