Logic in Prefabs
Prefabs contain their own Logic and it applies to all instances of the Prefab. The Prefab Logic can be incorporated into the Scene Logic via a Prefab Node, which can be found in the Logic Editor by choosing the Prefab tab on the left Menu.
To open the Prefab Logic graph in the Logic Editor either double-click the Prefab Node in the Logic Editor or the Prefab Asset in the Asset Manager. The user can then get started with:
Nodes
The Prefab Logic has four Nodes by default: Prefab Input, Prefab Output, On Creation, and On Destruction. These represent the Input and Output of the Prefabs as well as two events on the creation and destruction of the Prefab Node, respectively.
The Input and Output Nodes can have their Attributes customized: Input Sockets can be added to the Prefab Input Node and Output Sockets to the Prefab Output Node. These changes will then be reflected in the Prefab Node.
The On Creation Event Node is triggered once the Prefab is created in the Scene, which happens when the On Scene Show Event Node is fired or when an Object is created dynamically via Logic.
The On Destruction Event Node is triggered once the Prefab is destroyed in the Scene, which happens after the Scene is unloaded with Unload Scene or when the Object is destroyed via Logic with the Destroy Object Node.
Variables
It is possible to expose every Prefab Variable's default value to be set per instance from the Attribute Editor of the Prefab Instance. Currently only these Variable types are supported for this feature: AssetID, Binary, Boolean, Byte, Color, Float, Integer, MaterialID, MediaID, String, TextureID and Vectors.
The user must first access the Prefab tab of the Logic Editor, click on the Variables tab, and then click on Expose Icon of an already existing variable. If the Expose Icon is enabled for a Variable, then every instance of the Prefab has an Entry in its Attribute Editor under Prefab → Variables that shows the default value of the Variable that is settable as well.
The image below showcases all Variable types created in the Prefabs’s Logic Editor. However only the Variables having the Expose/Hide Icon are the ones that can be visible in the Attribute Editor of the Prefab's Instances. For example, the Variable named Byte of type Byte will not be visible because its Expose Icon has been disabled.
The next image shows how these Variables will be shown in the Attribute Editor of each instance of the Prefab where the user can set their default values. This is accessed by simple clicking on the Prefab Instance in the Scene Outliner and locating the Attribute Editor.
Last updated
