A ray marcher to demonstrate an IES point light source in a Cornell Box. You can use it with your own IES file.

The IES file format describes the angular distribution of intensity of a point light source following the IESNA LM-63 format.

You may find an online version for this application and another application to visualize the distribution itself.

Beware, type A and B are not supported and some type C files won't load if they don't follow the specifications

There exist other light formats such as EULUMDAT, CIBSE that are not handled by this viewer. Please find a way to convert to IES with a third party software,or contribute with your own Javascript Loader.

This viewer was made with three.js and was inspired by webgpu_lights_ies_spotlight and webgl_raymarching_reflect.

You may download IES files through this libray of IES files or from a light manufacturer.

If you are interested in IES lights made from different light source shapes, I have made a bunch of shaders on shadertoy.

• Light Intensity - Cornell Box
• Light Intensity - Function 3D
• Lambertian IES light intensity