mia_photometric_light Node explored – Tutorial

In this session we will have a closer look at the mia_photometric_light.

This node is not only allowing you to achieve more realistic lighting , but it will also make your GI solution much easier and faster to work with.
In the past one would have to adjust both photon Radius and Merge Distance. Now with this node the guessing portion is gone, you simply add the node to the light custom Shader and voala !

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The HD vr. can be found here.

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This entry was posted on Monday, September 20th, 2010 at 9:22 am and is filed under Maya, Mental ray. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

21 Responses to “mia_photometric_light Node explored – Tutorial”

  1. Tay A. Othman Says:
    September 21st, 2010 at 5:12 am

    Ash….you’re a creative egyptian…
    God Bless you Ya m3alim!!
    Regards

  2. Bert V. Says:
    September 21st, 2010 at 3:03 pm

    Awesome tutorial again, thank you !

    Do you know if the HD version is posted in THE AREA ?

    Regards, BV

  3. Ashraf Says:
    September 22nd, 2010 at 11:57 am

    HD is up

  4. Josh Says:
    September 22nd, 2010 at 11:49 pm

    Good work Ash, nicely explained :)

  5. David Says:
    September 24th, 2010 at 3:23 am

    Hey Ash. . .great tips. Don’t suppose you could tell me how to get the bsdf in the mia_material to work with this. Maya’s shading engine keeps inserting itself even with it turned off.

    Was hoping to combine a few of your tips with that.

  6. Dennis Jensen Says:
    September 30th, 2010 at 4:29 pm

    Very nice tutorial. Where are you from? I just noticed your accent.

    Anyway, I am doing some video tutorials my self, one of them is about basic lighting but a bit more basic and kind of a introduction to Maya lights. If you wanna see it look at this link:

    http://poly-face.com/showtut.php?id=8&part=1

    Great site by the way, I will look here from time to time.

    /Dennis Jensen

  7. Ashraf Says:
    September 30th, 2010 at 6:54 pm

    Thanks Dennis,
    I had a quick look at your site.. nice stuff … keep it up!
    In case if my site didn’t give it away.. I’m from Egypt :)

  8. Dennis Jensen Says:
    October 4th, 2010 at 1:46 pm

    Haha well I should have known :)

    Thx for your reply

    /Dennis J

  9. dave Says:
    October 25th, 2010 at 9:18 pm

    no mia_photometric_light shader in maya 8.5??

  10. Ashraf Says:
    October 25th, 2010 at 10:55 pm

    Only in 2011.

  11. Carlos Says:
    November 24th, 2010 at 1:06 am

    Thanks a lot, very well explained

  12. stussy Says:
    November 28th, 2010 at 11:22 am

    another great example of how not user friendly mr is. who came up with the mode switches? are they mad at Atudosek?

  13. dj Says:
    February 19th, 2011 at 3:37 pm

    does this only work with spot light?
    maya crashes when using this with area light

  14. Poora Says:
    February 25th, 2011 at 2:30 pm

    Hi
    Great tutorial. Well explained. I learned a lot from it. Thanks.
    Question:
    I created a simple setup for a studio shot using the technique explained in this tutorial. I have a area light with a photometric shader. And a blackbody shader in the color channel of the photometric. I’m using “intensity mode = 1″, so that I use the”manual Flux lm” to control the intensity of the light.
    The camera has a mia_photographic lens shader.

    The problem is the lights are barely visible in reflections. No matter how high the intensity. I was under the assumption that the light intensity would control the brightness of the light in reflections.

    The only solution I found was increasing the multiplier in the blackbody node. But then that throws off the lumen intensity control that I have established and tried to keep closer to real units.

    Any thoughts? Solutions?

  15. Ashraf Says:
    March 1st, 2011 at 10:41 am

    It works fine with Area light on my side
    Using Maya 2011 Advantage pack on Win 32

    Edit: I found the problem, if you scale the area light, then Maya will crash

  16. Ashraf Says:
    March 1st, 2011 at 10:42 am

    Once you enable the Flux, then the intensity is driven from that..to test
    get the reflective object very close to the light and see if that will change the reflection intensity, if it does..then May is behaving accurately.
    Does this help?

  17. GD Says:
    May 25th, 2011 at 12:54 pm

    Ashraf.. Nice tutorial.

    Like DJ said.. it crashes in Maya 2011.. I have the same problem in both 2011 and 2012.. Ashraf, did you have Emit Photons turned on?
    Cause for me the shader works generally.. Untill I tell it to emit Photons (GI needs to be on in Render Settings of course)

    CRASH!!

  18. Ashraf Says:
    June 2nd, 2011 at 5:30 am

    Can you post a sample file somewhere ?

  19. GD Says:
    June 6th, 2011 at 1:04 pm

    Link to the file — http://www.ginodammers.com/dump/WorksSometimes.zip

    I posted this issue last week on CGTalk as well..
    http://forums.cgsociety.org/showthread.php?f=87&t=982301

  20. Ashraf Says:
    June 7th, 2011 at 2:00 pm

    The BUG is comming from scaling the light.
    change the light scale to 1 1 1 and it will work

  21. Dav Says:
    May 11th, 2012 at 3:36 am

    Hi Ashraf, and thanks for this little tutorial.
    Are you able to have soft shadow using this node with raytrace shadow?
    I can’t have it working. With raytrace shadow I have sharp hard shadow like in your video.
    It only works with depth map.
    Did I miss something?
    And is it the only way to automaticly set the photon energy?
    Does this node is still usefull nowadays?
    Thanks

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