Just noticing something really weird with vray lights, When I select a whole lot of them and change their values through the Channel Box, it should update all their values but this doesn’t seem to happening with a couple of options
Can anyone confirm (using 28th April build here on Maya 2011).
1) Create IES light
2) Copy/Duplicate a few times
3) Open Channel Box, change units to Lumens (value should change to 18.85)
4) However select some of those lights individually now and they are still using default instead of lumens and still have the default intensity
The same thing happens when you change all the lights to use temperature instead of colour.
It seems it is not possible to do a mass change on multiple lights with these attributes.
Wondering if this is a v-ray AE script issue or Maya. Cheers
Another bug while I’m on the same topic.
1) Create V-Ray area light facing a plane
2) Duplicate said light and make them side by side so you can see the difference between the two
3) Select second light and through the channel box change the Color Mode to temperature and something like 200
4) Render - the light colours will still be exactly the same
5) Select the second light and open the Attribute Editor, the light will suddenly change in the swatch to red
6) Render - the light will now finally be correct
7) Using the channel box change the second temperature value to 8000
8) Render - the light will still be red
So it seems V-Ray lights do not work when changing these attributes through the Channel Box and will only update properly through the Attribute Editor
(Using April 28th build + Maya 2011)
Hi, sorry to bump my own thread - but is this only happening to me?
Anyone on Maya 2011 can confirm this workflow problem? It’s very hard to work with interior scenes as lights are not updating for the render. 
Yeah, Ive got exactly the same problems like you described. Very frustrating.
I can however change multiple values correctly through the attribute spread sheet.
In addition to that ,in previous versions I could look at (but not change) the render settings while rendering. Miss that.
Yes, the temperature updates the light color only when you change it through the Attribute editor. We nee to fix this. Thanks for the pointer.
Greetings,
Vladimir Nedev
About the render settings. Why can you not look at them now ? Is the UI update too slow ? You can fix this by checking “low thread priority” in Render Settings → Settings → System → low thread priority (somewhere at the bottom).
Greetings,
Vladimir Nedev
Thanks Vladimir (once again).
Can you use the attribute spreadsheet without issues? I would think that would be more reliable than the channel box for updating values across a large set of objects. You might see if that works for you in the short term for your current scene.
Thank you Vladimir! It works perfectly now, even in IPR mode. 