Lumen in Unreal Engine 5

Lumen uses a dynamic pipeline for indirect lighting. This makes it possible to change the geometry of a scene, materials and lighting conditions at any time. This significantly improves and simplifies the workflow of artists working with Unreal Engine 5. Furthermore, the lighting is updated immediately and waiting times until the final lighting quality is achieved are a thing of the past. In addition, geometrically precise reflections can be realized with Lumen and systems such as Nanite can be optimally integrated.

Like any new technology, Lumen still has some limitations and there are various teething problems. The first of these is the fact that Lumen Global Illumination cannot be used with Static Lighting in Lightmaps. Furthermore, the Lumen Reflections do not support multiple mirror reflections. In addition, water materials consisting of a single layer are not accepted by Lumen. It should also be noted that Lumen does not currently support “Scene Captures”, “Split-Screen” or “Forward Shading”. Furthermore, mirror reflection does not work on smooth surfaces such as walls or similar.   

The next generation of computer games and simulations requires advanced lighting technology that reacts dynamically to changes (time of day, weather) in the game world. The CGI industry has been searching for a solution for “global illumination” and reflections in real time for years. Nanite has already come a long way in this respect, but is still a long way from reaching its goal. However, Lumen Reflections are to be significantly improved in future versions of Unreal Engine 5, so that global illumination in “lightmaps” will be possible, for example. In addition, the render quality of projects based on static lighting is to be improved in the future.