Game development engines have become increasingly accessible in the last few years. Engines like Unity, which has always been free to use, and Unreal, which recently switched from a subscription-based service to a free service, allow independent developers access to the same industry-standard tools used by AAA publishers. While neither of these engines is open source, each has enabled the growth of open source ecosystems around it.
Within these engines are plugins that allow developers to enhance the base capabilities of the engine by adding specific applications. These apps can range from simple asset packs to more complicated things, like artificial intelligence (AI) integrations. These plugins widely vary across creators. Some are offered by the engine development studios and others by individuals. Many of the latter are open source plugins.
What is BLUI?
In Unreal Engine's earliest versions, the only means we had of creating UI in the game was either through the engine's native UI integration, by using Autodesk's Scaleform application, or via a few select subscription-based Unreal integrations spread throughout the Unreal community. In all those cases, the solutions were either incapable of providing a competitive UI solution for indie developers, too expensive for small teams, or exclusively for large-scale teams and AAA developers.
Installing and using BLUI
In our current project, we use BLUI to sync UI elements with the in-game soundtrack to provide visual feedback to the rhythm aspects of the game mechanics. It's easy to integrate custom engine programming with the BLUI plugin.
Implementing BLUI into Unreal Engine 4 is a trivial process thanks to the documentation on the BLUI GitHub page. There is also a forum populated with supportive Unreal Engine developers eager to both ask and answer questions regarding the plugin and any issues that appear when implementing the tool.
Open source advantages
Open source plugins enable expanded creativity within the confines of proprietary game engines. They continue to lower the barrier of entry into game development and can produce in-game mechanics and assets no one has seen before. As access to proprietary game development engines continues to grow, the open source plugin community will become more important. Rising creativity will inevitably outpace proprietary software, and open source will be there to fill the gaps and facilitate the development of truly unique games. And that novelty is exactly what makes indie games so great!