  Due to its ability to generate millions of particles, massively detailed
scenes and confusing artificial illumination with reality, the version 5 of
Unreal Engine promises unprecedented industrial applications. The paradigms and
aims of Unreal Engine contrast with the industrial simulators typically used by
the scientific community. The visual quality and performance of its rendering
engine increase the opportunities, especially for industries and simulation
business: where interoperability and scalability are required. The study of the
following issue `` Which architecture should we implement to integrate
real-world data, in an Unreal Engine 5 simulator and in a mixed-reality
environment? '' offers a point of view. The topic is reexamined in an
innovative and conceptual way, such as the generalization of mixedreality
technologies, Internet of Things, digital twins, Big Data but providing a
solution for simple and actual use cases. This paper gives a detailed analysis
of the issue, at both theoretical and operational level. Then, the document
goes deep into Unreal Engine's operation in order to extract the vanilla
capabilities. Next, the C++ Plugin system is reviewed in details as well as the
third-party library integration: pitfalls to be avoided are shown. Finally, the
last chapter proposes a generic architecture, useful in large-scale industrial
3D applications, such as collaborative work or hyper-connected simulators. This
document might be of interest to an Unreal Engine expert who would like to
discover about server architectures. Conversely, it could be relevant for an
expert in backend servers who wants to learn about Unreal Engine capabilities.
This research concludes that Unreal Engine's modularity enables integration
with almost any protocol. The features to integrate external real data are
numerous but depend on use cases. Distributed systems for Big Data require a
scalable architecture, possibly without the use of the Unreal Engine dedicated
server. Environments, which require sub-second latency need to implement direct
connections, bypassing any intermediate servers.
