Unreal Engine Integration with .NET

This section provides comprehensive documentation on integrating Unreal Engine with .NET technologies, enabling you to leverage the power of C# and the .NET ecosystem for game development.

Getting Started

Unreal Engine's C++ core provides the foundation for game logic and engine features. However, for certain types of development, such as tooling, server-side logic, or scripting, utilizing .NET can offer significant advantages in terms of rapid development and access to a rich library ecosystem.

Prerequisites

• Visual Studio 2022 or later (with .NET Desktop Development workload)
• Unreal Engine 5.0 or later
• Basic understanding of C# and the .NET Framework/Core

Setting Up Your Development Environment

To begin, you'll need to configure your Unreal Engine project to recognize and utilize .NET modules. This typically involves creating a specific project structure and enabling necessary plugins.

Core Concepts

Unreal Engine .NET Plugin

The official Unreal Engine .NET plugin acts as a bridge between the C++ Unreal Engine and your C# code. It exposes Unreal Engine functionalities to C# and allows your C# code to interact with the engine's systems.

Managed Game Instances

You can create managed game instances that run entirely within the .NET runtime, offering a more script-like development experience. This is particularly useful for rapid prototyping and complex game logic.

Interoperability

Understanding how to pass data and call functions between C++ and C# is crucial. The plugin provides mechanisms for this, including:

• Property Export: Exposing C++ properties to C#.
• Function Binding: Calling C++ functions from C# and vice-versa.
• Event Handling: Subscribing to and broadcasting Unreal Engine events from C#.

Common Use Cases

• Tool Development: Creating custom editors, asset management tools, and build pipelines using C#.
• Server-Side Logic: Developing dedicated game servers with the flexibility of .NET.
• AI Scripting: Implementing complex AI behaviors using C# for easier iteration.
• UI Development: Building user interfaces with .NET frameworks for rich UIs.

Code Examples

Creating a Simple C# Actor

using UnrealEngine.Runtime;
using UnrealEngine.Runtime.Core;

[UClass]
public class MyDotNetActor : Actor
{
    [UPoperty]
    public float Speed { get; set; } = 100.0f;

    public override void Tick(float DeltaTime)
    {
        base.Tick(DeltaTime);
        // Example: Move actor forward
        AddActorLocalOffset(Vector.Forward * Speed * DeltaTime);
    }
}

Interacting with C++ Functions

Suppose you have a C++ function in your game mode like void BroadcastGameMessage(const FString& Message);.

using UnrealEngine.Runtime;
using UnrealEngine.Runtime.Core;

// Assuming you have a reference to your GameMode
var gameMode = GEngine.GameMode;
var message = "Hello from C#!";
gameMode.CallNativeFunction("BroadcastGameMessage", message);

Troubleshooting Common Issues

• Build Errors: Ensure your .NET SDK and Unreal Engine versions are compatible.
• Runtime Crashes: Check for unhandled exceptions in your C# code and ensure proper marshalling of data types.
• Plugin Not Loading: Verify that the .NET plugin is enabled in your project's `.uproject` file.

Further Reading

• Official Unreal Engine .NET Documentation
• Unreal Engine .NET GitHub Repository