IES Profiles

IES profiles are files that store information on light shape and intensity so you can mimic these lights accurately in a digital design package plus you get 10 cool points every time you use one.

Random googled images to demonstrate.




You can grab photometric data easily from any lighting manufacturer like General Electric Lighting or Lithonia Lighting just to name a couple. And there is even a free IES viewer, called well....IES Viewer. It was created by Andrey Legotin and it allows you to view all the information associated with the light profiles and there's even a really handy render feature so you can see exactly how the light looks without having to setup a scene in your 3D package just for that yay.

   


Scene setup in Maya: Really simple geometry, walls, ceiling, floor and a few light fixtures. And a camera with a photographic exposure lens shader with a Cm 2 factor of 10000 (have to crank up the value or it'll be too dark) Without the exposure lens shader, you'll get horrifically blown out highlights and hotspots so fast it'll make your head spin. Now on to the lights, I created some point lights and positioned them near my fixtures. Why point lights? They have a special little slot for light profiles in the Mental Ray tab, and clicking that all too familiar checker box will automatically create a light profile node, from there you can browse for the IES file of your choice.


 


Hit render....nothing.... Apparently you have to set a decay rate on the light, I chose quadratic and to keep pace with the light now dying off with distance, the intensity must be increased (don't be shy with the numbers :) and BAM! juicy photometric lights in all their glory hell yeah! 

 
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::