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! 

 
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The Mia_Material_X

    Well, I made my own little shader swatch scene thingy, I had to (I was using spheres prior to this, don't ask, just chalk it up to laziness and back away slowly). Since I'm rendering out swatches, thought I'd write about it, might help a new user, who knows :o).

    The mia_mat_x is one of my favorites, if not my favorite shader, yeah that's right I said it, it's out there now so deal with it. It's a very versatile shader, from glass, to plastic, rock, wood, metal , even the crud stuck in that creepy guy's teeth, it can pretty much do it all. Migrating over from shaders like the Maya Blinn where there are independent channels for qualities like reflectivity and specularity, the mia_mat took a little getting used to since it's a physical shader, good thing the attributes are self explanatory . I tried the whole "use a preset and reverse engineer 'em" method to know what makes that particular "look" tick. Well, that didn't work out too well as I wasn't familiar enough with the shader's default attributes to even know most of what was changed so I decided to poke around 'til I knew what attributes did what.

Mia_mat Caustics

As far as generating caustic patterns, there are a few things that I need to setup, two of the most obvious ones are, telling the mia_mat to use caustics instead of transparent shadows and turn on caustics in the MR render settings. On the caustic settings, I usually take the ol' cheapo route of lowering caustic accuracy to say about 20 or 30 and use the cone filter, this enables me to get sharper patterns without having to juice up the photon count emitted from the light too much.