To use Post Process, you need a Post Process Volume in your scene:
Go to the Modes tab (if you closed it, press Shift + 1).
Select the Volumes tab.
Drag and drop Post Process Volume into the scene:
You now have a Post Process Volume in your scene. However, it only shows the effects when the player is inside that volume. To make it affect the whole scene perform the following steps:
Select Post Process Volume
In the Details panel, scroll down and expand the Post Process Volume section
Enable Unbound
Enabling Unbound will ignore the bounds of this volume and affect the whole scene. Now, let's take a quick look at these Post Process settings:
Priority: If multiple volumes are overlapping each other, then the volume with higher priority overrides the lower one.
Blend Radius: This is the radius of the volume used for blending. Generally, a value of
100
works best. This setting is ignored if you have Unbound enabled.Blend Weight: This defines the influence of properties.
0
means...