Lighting our scene with image-based lighting

This introductory chapter has so far laid out some of the foundations of the PBR workflow that Unreal introduces. With that pipeline as our main focus, we've already taken a look at several of its key components—namely the different material parameters and shading models.

However, as we've said in the past, PBR takes information from the lights in our scene to display and calculate how everything should look. So far, we've focused on the objects and materials that are being rendered, but that is only part of the equation. One of the other parts is, of course, the light emitters themselves.

Lights are crucial to the PBR workflow. They introduce shadows, reflections, and other subtleties that affect how the final image looks. They work alongside the materials that we've previously applied by giving value to some of the properties we set up. Roughness textures and normal maps work in tandem with the lights and the environment itself. And all of this combined is also an integral part of the pipeline we are looking at in this introductory chapter.

With that as our objective, let's create in this recipe different types of lights and see how they affect some of the materials we have previously created. We'll be taking a look at the all-important High-dynamic-range imaging (HDRi) maps, 32-bit textures, which include lighting information in them and that can be used to light up a scene. Let's get started!