There are a couple of methods for implementing a generic background actor in Unity. The simplest one is to make it a prefab. It can be a background actor that attaches to a root object. Appearance changes are routed as Unity events. However, because it is a prefab, you need to implement this behavior on your own. This approach will not work well with most actor-related features, including camera resizing and scaling.
One of the best and most flexible ways to implement a background actor is to use a generic background. This type of actor is based on a prefab and attaches a behavior component to the root object. This behavior component receives appearance changes as Unity events and routes them appropriately. You can create your own generic backgrounds using templates or create a custom background actor based on the image you’ve already created. If you want to customize a generic background, you can modify the settings of the default prefab.