Installing the Plugin¶

This section explains how to install Modular Building System in an Unreal Engine project.

The plugin's core systems are implemented in C++, but the standard workflow supports Blueprint-only projects. Under normal circumstances, Blueprint projects do not need to create C++ classes or modify the project's Build.cs file.

Requirements¶

Item	Requirement
Unreal Engine	Unreal Engine 5.4-5.8
Project Type	Blueprint or C++
Plugin Type	Runtime Plugin
Operating System	Windows
Network Mode	Single-player and Listen Server
Dedicated Server	Refer to the notes for the current version

Engine Version

Use the Unreal Engine version that matches the plugin package.

C++ plugins built for different engine versions generally cannot be used interchangeably.

Plugin Dependencies¶

The plugin uses several built-in Unreal Engine modules, including:

Gameplay Tags
Niagara
Networking
Hierarchical Instanced Static Mesh
StructUtils: Required only for Unreal Engine 5.4. StructUtils is a built-in Unreal Engine plugin. In Unreal Engine 5.5 and later, the required struct utilities are provided by CoreUObject.

These dependencies are loaded automatically by the plugin modules. Under normal installation conditions, the project's Build.cs file does not need to be modified manually.

Installing Through Fab¶

After obtaining the plugin through Fab, install it for the corresponding Unreal Engine version.

The basic process is as follows:

Find Modular Building System in your Fab Library.
Select the target Unreal Engine version.
Install the plugin for that engine version.
Start or restart Unreal Editor.
Open the project in which you want to use the plugin.
Enable the plugin in the Plugins window.

If the plugin is already installed for the current engine version, proceed directly to Enabling the Plugin.

Installing the Plugin in a Project¶

If you received the plugin as a standalone folder, place it in the project's Plugins directory.

The project structure should look similar to the following:

YourProject/
├── Config/
├── Content/
├── Source/
├── Plugins/
│   └── ModularBuildingSystem/
│       ├── Config/
│       ├── Content/
│       ├── Resources/
│       ├── Source/
│       └── ModularBuildingSystem.uplugin
└── YourProject.uproject

If the project does not contain a Plugins folder, create it manually:

YourProject/Plugins/

Then copy the entire plugin directory to:

YourProject/Plugins/ModularBuildingSystem/

Do Not Copy an Extra Parent Directory

ModularBuildingSystem.uplugin must be located directly in the plugin's root directory.

Correct:

Plugins/
└── ModularBuildingSystem/
    └── ModularBuildingSystem.uplugin

Incorrect:

Plugins/
└── ModularBuildingSystem/
    └── ModularBuildingSystem/
        └── ModularBuildingSystem.uplugin

Installing the Plugin in the Engine Directory¶

You can also place the plugin in the Unreal Engine plugin directory:

UnrealEngine/
└── Engine/
    └── Plugins/
        └── Marketplace/
            └── ModularBuildingSystem/

The differences between project-level and engine-level installation are as follows:

Installation Type	Description
Project-level installation	The plugin is available only to the current project.
Engine-level installation	The plugin is available to multiple projects using that engine version.

Project-level installation is recommended during development and testing because it makes plugin version management easier and does not affect other projects.

Enabling the Plugin¶

After opening Unreal Editor:

Open Edit.
Select Plugins.
Search for:

Modular Building System

Enable the Enabled checkbox next to the plugin.
Restart the project when prompted by the editor.

After restarting, the plugin modules will be loaded when the project starts.

Verifying the Installation¶

After enabling the plugin, use the following methods to verify that it was installed correctly.

Check the Plugins Window¶

Open:

Edit → Plugins

Search for Modular Building System and confirm that the plugin is enabled.

Check Project Settings¶

Open:

Edit → Project Settings

Search for:

Building

If the settings for Modular Building System are available, the plugin settings module has loaded correctly.

Check the Content Browser¶

If the plugin includes example content, enable the following option in the Content Browser:

Settings → Show Plugin Content

After enabling it, the plugin content directory will be visible in the Content Browser.

The plugin's core C++ functionality does not depend on whether Plugin Content is visible. This option only controls whether plugin assets are displayed in the Content Browser.

Blueprint-Only Projects¶

The plugin can be installed in Blueprint-only projects that do not have a project C++ module.

The standard Blueprint workflow includes:

Adding a BuildingBuildComponent
Creating building data assets
Configuring a building Mesh or Actor Class
Entering building mode
Confirming, moving, and removing buildings
Listening for building result events
Using multiplayer building features
Implementing the Blueprint interfaces provided by the plugin

Normal usage does not require:

Creating an empty C++ class
Modifying the project Build.cs
Modifying the plugin source code
Compiling the plugin manually

Recompilation Prompt

If a Blueprint project reports that plugin modules are missing or need to be recompiled, confirm the following:

The plugin version matches the Unreal Engine version.
The plugin package contains compiled binaries for the target platform.
The plugin files are not corrupted.
The plugin is not located inside an incorrectly nested directory.

C++ Projects¶

For standard usage, projects containing C++ code do not need to add the plugin module as a dependency manually.

You only need to add the dependency to the project module's Build.cs file when your project C++ code directly includes plugin headers or calls plugin APIs.

For example:

PrivateDependencyModuleNames.AddRange(
    new string[]
    {
        "ModularBuildingSystem"
    }
);

If plugin types must be exposed through the project's public header files, add the dependency to the following list as appropriate:

PublicDependencyModuleNames.AddRange(
    new string[]
    {
        "ModularBuildingSystem"
    }
);

In most cases, PrivateDependencyModuleNames should be preferred.

After modifying Build.cs, regenerate the project files and compile the project.

First Launch¶

After enabling the plugin for the first time, check the following:

The plugin is enabled successfully.
The plugin settings are visible in Project Settings.
The collision channels required by the plugin are configured.
The Gameplay Tags used by the plugin are loaded correctly.
The example content can be displayed.
BuildingBuildComponent can be added to a Blueprint Actor.
The building data assets provided by the plugin can be created.

Pre-Packaging Checklist¶

Before packaging the project, confirm the following:

The plugin is enabled in the target project.
The plugin version matches the target engine version.
Building data assets can be loaded correctly.
Plugin content has not been excluded incorrectly.
Required Gameplay Tags are included in the project configuration.
Required collision channels and collision profiles have been created.
The Blueprint-only project can be packaged successfully using the Development configuration.
Multiplayer functionality has been tested on both the client and server.

Do not validate the plugin only in editor PIE sessions. Before release, test at least one standalone session or packaged Development build.

Troubleshooting¶

The Plugin Does Not Appear in the Plugins Window¶

Check the following:

ModularBuildingSystem.uplugin exists.
The plugin directory is located in the project's Plugins folder.
There is no additional nested directory with the same name.
The plugin descriptor file is not corrupted.
The current Unreal Engine version is supported.

The Plugin Was Built for a Different Engine Version¶

This means that the plugin package does not match the current Unreal Engine version.

Install a plugin package that matches the current Unreal Engine version. Ignoring this warning is not recommended.

The Project Does Not Start After Enabling the Plugin¶

Close the editor temporarily, then open:

YourProject.uproject

Check the Plugins configuration, or temporarily move the plugin directory out of the project to determine whether the issue is caused by plugin loading.

Also check the project logs in:

YourProject/Saved/Logs/

Plugin Assets Are Not Visible in the Content Browser¶

Enable:

Content Browser → Settings → Show Plugin Content

Building Data Asset Cannot Be Found¶

Confirm the following:

The plugin has been enabled and the project has been restarted.
You are creating a Data Asset.
The plugin modules have loaded successfully.
You are not using an incompatible plugin version.

Next Step¶

After installation, continue with:

Quick Start