Release: wom_archlight 1.0 - physically accurate light shader


Maya users,

I have today released the 1.0 version of my light shader that I have been working on for some time, and that has been tested by many of the fine people on this forum. In case you missed the original thread, here is a quick list of the main features:
[li]Support for IES light profiles with real light profile intensities, and ability to scale profile intensity using real world units[/li][li]Support for photometric (candela, lumen, lux) or radiometric (watt, watt/s, watt/m2) real world-units[/li][li]A photon emitter that supports light profiles, area lights, and is linked to direct light intensity[/li][li]Ability to use area lights with soft shadows while retaining IES profile sharpness/definition[/li][li]Support for color temperatures[/li][li]Light profile rotation[/li][li]A shader to create object/geometry lights[/li][li]A separate simple texture shader to add light profile support to other nodes[/li][li]Works with both Maya and Softimage on Windows 64-bit and 32-bit, Linux 64-bit, and MacOSX (Maya only).[/li][li]Completely free and fully open source (BSD license) with minimal restrictions, so you can compile for other platforms, incorporate the code into other free or commercial projects and redistribute.[/li][li]Comprehensive manual[/li][/ul]The goal of the shader is really to be the only light shader for mental ray you will ever need to use. Please post if you run into any trouble or bugs. Any comments, feedback or nice renders are always appreciated. Enjoy!

Updated to version 1.23

Here are the links to the latest version (version 1.23):

Note that version 1.23 has no improvements from the 1.22 test DLLs that were floating around previously. The only purpose of 1.23 is to provide an updated full package that provides support for Maya/Softimage 2010 on all platforms.


That’s fantastic.

Thanks you for all your hard work.


Dude, this is awesome.
Thanks so much for all your hard work.:applause:

I’m going to post this in Pixar forums to see if someone can compile this for RMS!


Thank You Very Much wombat:bowdown::thumbsup:


I’d say you’re well on the way to achieving that goal. I dont know anything about IES but I’m getting great results so far, and the object light is really nice. Thanks wombat :applause:

– David


photon emission through the light profile…just because of that im like a kid on christmas day right now, not to mention the rest of those awesome features
Thank YoU!!!


the wonderful day of an easy and practical photometric lighting workflow in Maya is finally here, thank you wombat.

this will help all mayan arch viz users like me a huge amount.


Can’t wait to start using this! You’re a star!



Thank You so much Wombat :thumbsup: Awsome features


I wonder if anyone here has used LightGirl 1.0?


thanks again.


Hi, I can’t download it megaupload. Please re upload rapidshare. Thanks.


Hi Gandalf3d,

It is also uploaded at (it is the exact same version). Here is the link:

Hopefully that should be easier for you to access. Let me know.


wombat, thanx again for all you efforts :smiley:

this is my “little” wish for v2.0, importance sampling :wink: eheh i know it’s a little bit complicated, but… it’s a wish…


Hi Wombat, I’d just like to add my thanks too for this great shader. Also there’s the documentation and last but not least the source code. I find it a great education to go through peoples source codes, and I really appreciate you releasing it.
Many thanks


Thank you wombat. I download it :slight_smile:


oh yeah, little wish? :applause:


I don’t know if is possible, but i have a wish. On the final gather computing, the shadow rays is more more and more. This problems is the same of the mib_light_photometric.
Is possible to do any satisfaction reduce shadow rays on your shader?

Thank you very much.



@dagon: Hehe, importance sampling sounds complicated but I will see what I can do.

@ysejam: I will take a look into the shadow ray issue. I assume you mean that shadows get very slow when using FG. Are there any mental ray shaders that do not have this problem? I know that physical_light has a threshold mechanism that maybe I could use (if it would solve the problem). Thanks.


i dont know if your shader already use it, but there is a mechanism to reduce shadow samples for secondary rays in the area lights
3ds max use the default setup, 1 sample(very bed IHMO), so, for secondary rays you get a noise look
maya instead let you control this mechanism, there is a “low samples” and an “high sample limit”, the number of “low samples” it’s used for secondary raytracing and also for the FG

dario, when you need to use many lights, try to reduce the falloff, this reduce the “phisical correctness” of the lighting, but it help a lot to reduce rendertimes