Image-Based Lighting
Lighting a scene from an environment image
Also known as: IBL · Environment lighting · HDRI lighting · Skylight · Environment map lighting
Definition
Image-based lighting, or IBL, lights a scene using an image of an environment, usually an HDRI or cubemap, as the light source. The image gives both soft diffuse light from every direction and sharp reflections on shiny surfaces, with brighter parts of the image acting as stronger lights. It is a fast way to get realistic, natural-looking lighting and reflections, and is the base of most previews in Substance Painter, Marmoset Toolbag and Blender.
In production
Choose an HDRI that matches the mood, such as a studio for assets, a sunny sky for outdoor materials, and rotate it to place the light and shadows. Check a material under several HDRIs to see that it holds up in different conditions. In game engines the same idea is used through sky lights and reflection probes, which capture the environment around them.
