Blueprint children

The goal: a Blueprint whose parent is a Rust class, to assign the assets the class needs (meshes, sounds, input actions, widget classes) and to tune its values, without touching Rust.

This is how every Rusteal template works: the Rust class declares the properties, and a Blueprint child named BP_<Class> fills them in. The game then uses the Blueprint, not the Rust class directly.

Creating the Blueprint

1. In the Content Browser, open the folder the Blueprint goes in.
2. Right-click an empty area and choose Blueprint Class.
3. In the Pick Parent Class window, expand All Classes.
4. Type the Rust class’s name in the search box (Turret).
5. Select the class in the list and click Select.
6. Name the new asset BP_Turret and press Enter.

Screenshot: the Pick Parent Class window with All Classes expanded and the Rust class found by the search. (images/classes/pick_parent_class.png)

Filling in the properties

1. Double-click BP_Turret to open it.
2. Click Class Defaults in the toolbar.
3. In the Details panel, find the Rust class’s properties under their categories, and set them: pick the sound in Fire Sound, the projectile Blueprint in Projectile Class.
4. Click Compile, then Save.

Screenshot: the Class Defaults of BP_Turret with Fire Sound and Projectile Class assigned. (images/classes/class_defaults_assigned.png)

The components the Rust class declares are in the Components panel: select one to give it a mesh or a material.

Using the Blueprint

Place BP_Turret in the level by dragging it from the Content Browser into the viewport, or spawn it from Rust through a SubclassOf<T> property that holds it (see Spawning actors).

Game mode, pawn and controller

A game mode names the pawn and the controller the game uses. With all three in Rust:

1. Create a Blueprint child of each: BP_MyGameMode, BP_MyCharacter, BP_MyPlayerController.
2. Open BP_MyGameMode, click Class Defaults, and in the Details panel, under Classes, set Default Pawn Class to BP_MyCharacter and Player Controller Class to BP_MyPlayerController. Compile and Save.
3. Open the level, and in the World Settings tab (Window > World Settings), set GameMode Override to BP_MyGameMode.

Or, for every level of the project: Edit > Project Settings, Maps & Modes, Default GameMode.

Screenshot: the World Settings tab with GameMode Override set to the game mode Blueprint. (images/classes/world_settings_game_mode.png)

Rules for Blueprint children

• Data, not logic, for what Rust does. A Blueprint child that implements an event the Rust class implements replaces the Rust code for it. Keep the Blueprint’s graph for the BlueprintImplementableEvents the Rust class declares for it.
• Values changed in the Blueprint win. A value set in the Blueprint’s Class Defaults overrides the Rust default. The arrow next to a changed value resets it.
• Hot reload keeps them. When the Rust class changes shape, its Blueprint children move to the new class with their values. See Hot reload.