How to use Blueprint Interfaces in Unreal Engine 5 in less than 3 minutes

Summary

In this tutorial, Joey Chimney demonstrates how to use Blueprint Interfaces in Unreal Engine to enable communication between actors. The process involves creating a Boost actor with a Cube, implementing a Blueprint Interface, and setting up an event for interaction with the player character. By using Blueprint Interfaces, external actors can trigger events in other actors, allowing for flexible and efficient communication. Additionally, the tutorial highlights the performance benefits of using Blueprint Interfaces over casting, as well as the ability to pass dynamic values like boost power and direction across actors in the scene.

Takeaways

• 😀 Blueprint interfaces in Unreal Engine allow actors to send and receive information between each other.
• 😀 A blueprint interface is a collection of functions and events that can be implemented across multiple actors.
• 😀 To use a blueprint interface, create a new actor, add a cube, and set up a collision for overlap events.
• 😀 A blueprint interface is created by right-clicking and selecting 'Blueprint Interface', then adding functions like 'BoostThing'.
• 😀 Implement the interface in the actors that need to use it through the 'Class Settings' in each actor’s blueprint.
• 😀 After implementing the interface, use the 'Actor Begin Overlap' event to trigger interactions between actors.
• 😀 To send messages through the interface, connect the event to a reference of the target actor and call the function.
• 😀 For the player character, set up an event to respond to the boost action, such as launching the character into the air.
• 😀 Blueprint interfaces can be used to send additional data such as boost power, direction, and sound effects.
• 😀 Blueprint interfaces are a more efficient alternative to casting references, providing better performance in your game.
• 😀 Testing the interaction involves placing the Boost actor in the scene and running the game to check the functionality of the event.

Q & A

What is the main purpose of using Blueprint Interfaces in Unreal Engine?

Blueprint Interfaces allow you to send and receive information between actors in Unreal Engine. They act as a communication bridge, enabling different actors to interact with each other through functions and events.

How do you create a Blueprint Interface in Unreal Engine?

To create a Blueprint Interface, right-click in the content browser, select 'Blueprint' and then 'Blueprint Interface.' Name the interface, and within it, you can define functions that will be used by different actors.

What is the process of implementing a Blueprint Interface in an actor?

To implement a Blueprint Interface in an actor, go to the actor's 'Class Settings,' click on 'Implemented Interfaces,' and add the desired interface. Afterward, compile and save the actor.

What role does the 'Actor Begin Overlap' event play in the script?

The 'Actor Begin Overlap' event is used to trigger the Boost function when another actor (like the player character) collides with the boost actor (the cube). This event sends a message to invoke the boost action.

What is the purpose of using the 'Launch Character' node in the player character blueprint?

The 'Launch Character' node is used to apply a force to the player character, effectively launching them into the air when they collide with the boost actor, based on the values defined in the blueprint interface.

How does the Blueprint Interface improve performance compared to using casts?

Blueprint Interfaces are a more performant alternative to using casts because they are a form of soft reference, meaning they allow interaction between actors without needing to specifically cast to a certain class type, which can be more resource-intensive.

Can Blueprint Interfaces carry additional information beyond just sending messages?

Yes, Blueprint Interfaces can carry additional information. In the example provided, the Boost interface also includes inputs such as the power of the boost, the direction of the boost, and sound effects, allowing each boost actor to have unique properties.

What is the significance of the 'Get Actor of Class' node in this example?

The 'Get Actor of Class' node is used to target a specific actor in the scene—in this case, the player character—so that the Boost function can be called on that particular actor when the boost event is triggered.

How can you modify the values of each boost actor in the scene?

You can modify the values for each boost actor by exposing variables within the Boost actor, such as power or direction. These variables can be adjusted individually for each instance of the Boost actor placed in the scene.

What is the benefit of using Blueprint Interfaces in game development?

Blueprint Interfaces simplify interactions between different actors without tightly coupling them. They make the code more modular and reusable, reducing dependencies and improving overall maintainability and performance.