Light emission from IBL node increase render time in Maya 2011

Compared to previous versions of Maya the function of using Light Emission from the IBL node will dramatically increase render time.
This matter has been logged as BUG and currently under investigation by the development team.
As a workaround you can use under the "Light Emission" tab of the IBL shape, keep the "Quality U" and "Quality V" settings no higher than 7.  This is because the bug kicks in only when there is more than 56 IBL samples.

If this produces too poor quality results (grainy images), you can compensate by boosting the Sample Level under Render Settings->Quality->Anti-Aliasing Quality->Raytrace/Scanline Quality.

Workaround 2

1. select the miDefaultOptions node. 
2. In the attribute editor, open the "String Options" section.
3. Hit the "Add New Item" button.
4. Scroll to the bottom of the String Options section to find the new added
blank item.
5. Fill in the new item as follows:
 - Name: environment lighting mode
 - Value: light
 - Type: string
6. When doing preview renders in the render view, to get "smooth" results
without too many samples, set the value to "approximate" instead of "light"

Thanks to Justin Novosad for his feedback

Comments

[Ivaylo Danev]

I dont seem to find any difference when I turn on or off the Light Emission with 7/7 Quality U/V when "Environment lighting mode" is turned on ( different than "off")? When I boost the Quality of the U/V and turn off the ELM, I get a completely different result. I am using Maya 2011 though, is this bug fixed there, and can you please tell me what's the true IBL - When Light Emission is on or when Environment lighting mode is on?

I love your posts here, at least they tell the truth.

-Ifko

[meizitang]

I've been using it for quite a while now. I never had problems with it.

[David]

My bad, first section should be:

setAttr -type "string" miDefaultOptions.stringOptions[35].name "environment lighting mode";

[David]

The new built-in IBL (not exposed) which is the workaround is preferred. Comparable to Vray and faster when used with the progressive sampler.

setAttr -type "string" miDefaultOptions.stringOptions[35].name "environment lighting";
setAttr -type "string" miDefaultOptions.stringOptions[35].type "string";
setAttr -type "string" miDefaultOptions.stringOptions[35].value "light";

setAttr -type "string" miDefaultOptions.stringOptions[36].name "environment lighting quality";
setAttr -type "string" miDefaultOptions.stringOptions[36].type "float";
setAttr -type "string" miDefaultOptions.stringOptions[36].value "1.0";

setAttr -type "string" miDefaultOptions.stringOptions[37].name "environment lighting shadow";
setAttr -type "string" miDefaultOptions.stringOptions[37].type "string";
setAttr -type "string" miDefaultOptions.stringOptions[37].value "transparent";

1.0 is extremely high quality, drop to about .2 to start. And you can change the lighting mode to "approximate" instead of "light" for a less accurate but faster render.

[mindy]

The old Light Emission mode is sooooo out of date and useless. Take a look at Vray :) niceeeeeee

[John Chen]

Hi, has this issue been addressed in SP 1 for maya 2011?