Sometimes, by design, the map or level has to reflect something. Having a mirror, water drops, or metallic parts around will never look real without reflecting some parts of the environment. And that's when it is time to use Reflection Capture.

Reflection Capture is not only the name of an actor you use inside the editor, but also the functionality itself at the same time. While having real-time reflections is really costly performance-wise, it is possible to reduce that cost using Reflection Capture.

Simply, it is the same concept as lightmaps; you can bake those things earlier in a sort of a map and use them later at run-time. Unreal Engine has inside its toolset what is called Reflection Environment via the Reflection Capturers.

The Reflection Environment toolset provides efficient reflections in all the directions of the scene, just like metal surfaces (the idea is to have objects that have materials with a high and noticeable specular and a low roughness values, so...