Unreal Engine 4 has 3 main methods to performing depth of field effects: Gaussian, Bokeh and Cirlce DOF. Let’s take a quick look on them and try to use different settings in different scenes.
Depth of Field methods in Unreal Engine 4
Gaussian Depth of Field is a cheap and fast method to add blur effect into your scene. It’s a universal method, which will be a good addition to many kinds of games. I used Gaussian DoF in my Projectiles Pack with those settings:
Bokeh Depth of Field gives you the best quality, but it’s rather expensive and should primarily used in making cinematics and showcases.
Here the same scene with Bokeh DOF:
You can use custom textures or use the default one to get shapes that can be seen in photos when objects are out of focus, like in this picture:
Circle Depth of Field is rather a new method, which has good performance and nice look. I personally found that it is great for big landscapes, like that:
As you can see, the mountains have pretty nice soft blur effect. If you will use Gaussian or Bokeh methods, then it will take more time for tweaking parameters to achieve a good result(in this scene I didn’t find good settings with those methods). In the case of circle DoF you need to tweak only two parameters: Aperture and Focal distance. The lower aperture is, the more blur you will get. Try to change the focal distance to move focus.
I used these values for the scene above: Aperture = 32.0, Focal distance = 15.0.
You can apply these Depth of Field methods by using Post Process Volume(don’t forget to check unbound checkbox, if you’re planning to use this effects globally).
If you want to get more technical details about these methods, you can read the documentation here.