Leveraging DearImGui in Unreal
If we discuss tooling, I'll invariably talk about DearImGui and how it should be an essential part of all developers tool belt. It's just the kind of lib that sets such a high standard of "it just works" that even if you don't have an immediate need, I think you should check it out. On top of that, I strongly believe that knowing about the Immediate mode style of API has some great benefits for development and writing user facing libraries, and this library is an excellent example of that style.
We'll be building this small debugging tool that allows us to pick an actor in the scene with a line trace, and show some data about the Mesh components attached to it. We'll also see how to add buttons that can call arbitrary code on those components. It took me about 30 minutes to build, and we'll see how little UI code we end up needing 😁
First of all we need to understand that DearImGui is a completely independent library, it's meant to be plugged into any arbitrary game engine/rendering backend, and as such you can't just go on the imgui github and hope for it to work out of the box in Unreal. As such, in usual Unreal fashion, we want to find a plugin that already does the implementation for us !
