There’s currently no built-in support for IES light sources in Blender & Cycles.
We already know that Blender 2.8 will have the feature built into it (which is great news!), and there’s an addon that provides the functionality, but I wasn’t satisfied with it’s workflow, not being integrated well into Cycles.
So I decided to develop a custom Cycles shader (node group) that will provide realistic IES like spotlights in a convenient customizable way.
The Shader I developed is called CG-Lion Spotlight Presets Pack 1.0 and is available for purchase on Blender Market.
It doesn’t load external IES files, but instead has a pre-configured library of 20 spotlights shapes, and also provides features that are not available in IES lighting like tweaking the spotlight beam focus, adding a chromatic dolor dispersion effect, and producing a correctly bright surface at the light source.
IES stands for Illuminating Engineering Society, it is the organization responsible for creating and maintaining industrial standards for design and manufacturing of artificial light sources.
In 3D rendering, an IES file or “photo-metric file” is a text file containing a photometric description of a light source’s beam spread , pattern and intensity, allowing for faithful depiction of the light source in 3D renders.
Most modern 3D rendering software support IES lights, that is allow loading IES files into the software and lighting the 3D scene using the light source described in the IES file.
Lighting manufacturers make measurements of their light fixture model’s physical light output and create IES files available for download on their websites.
This allows architects, lighting designers, and interior designers to download the files and realistically visualize the light sources effect on their projects.
CG artists use IES lights to add realistic spotlight beam patterns to their renderings and animations, such that can’t be created using regular simple 3D light sources.
Examples of IES lights rendered with V-Ray for 3ds max: