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phleX
08-04-2010, 04:39 PM
Hi,

After upgrading to Maya 2011 I was wondering why most of my renders suddenly seemed to take much longer than in 2009 (skipped 2010).
After some time of testing I was able to isolate the problem.
In most of my scenes I make use of Image Based Lighting with Light Emission turned on.
Maya 2011 seems to have a problem with this.
I set up a scene with just a sphere object and an IBL node with an HDR image. For the sphere I used the MI Car Paint Phen X Passes shader, which I use a lot.
As long as Light Emission is turned off in the IBL node's attributes, the renders in 2009 and 2011 look the same and also the render time is about the same.
However, when I turn on Light Emission in 2009 the object is rendered much brighter (as expected), whereas in 2011 it's rendered only insignificantly brighter and the render takes almost 5 times longer!

Maybe there's some new option that has to be checked or unchecked or whatever to change this, but if so, the people at Autodesk don't seem to know about it. I posted the issue to the Autodesk support, also pointing out that it makes the upgrade to 2011 next to useless for me, but the answer was rather succinct: "This light emission problem has been reported elsewhere. I will pass this on to the development team".
That means it can take something between a week and eternity to solve the problem.

Unless they solve it within the next few days, however, I have to switch back and reconfigure the machines to Maya 2009 which feels like a bad joke to me.

Did anyone here make the same experience? Can you reproduce the problem, setting up the described scene, or does 2011 behave like 2009 on your machines? Anyone found a workaround or the magic "behave like 2009 option box"?

Cheers, phleX

http://img843.imageshack.us/img843/3844/maya20092011ibllightemi.jpg

Eshta
08-04-2010, 07:03 PM
ya, I got the same problem

mduvekot
08-05-2010, 04:56 PM
Same here. No contribution and severe performance impact. I've logged bug 364332 with Autodesk. http://bugs.thnkr.com/view.php?id=260 Did you hear back from them?

chuckie7413
08-05-2010, 05:46 PM
i will say tho that the emit light ability of the IBL node is very poor and would not recommend using it.

Since maya 2010 a new image based lighting solution has made and samples your hdr in a much better way (importanced) compared to the old emit light function.

See here for sampling explanations:

http://forums.cgsociety.org/showpost.php?p=2797452&postcount=31

And here for the new image based lighting solution:

http://forum.mentalimages.com/showthread.php?t=5717

and this thread has some tests that involve the new ibl solution:

http://forums.cgsociety.org/showthread.php?f=87&t=870682&page=1&pp=15

Best,

Rich

mduvekot
08-05-2010, 05:57 PM
Ah yes, the method wasn't any good, but there was no alternative i 2009 and breaking things that worked in 2009 and 2010, however poorly, in 2011 is to introduce a regression. Regressions are bad. They should be fixed.

Ash-Man
08-06-2010, 03:38 AM
Obviously this has to be fixed, but you can try this as a workaround
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.

Eshta
08-06-2010, 04:50 PM
Ashraf Basha :)
I see you placed another workaround on the blog
http://mayastation.typepad.com/maya-station/2010/08/light-emission-from-ibl-node-increase-render-time-in-maya-2011.html

phleX
08-10-2010, 10:51 AM
Unfortunately the two workarounds suggested by Autodesk are not useful at all for me.
How can increasing the Anti-Aliasing Quality compensate for a lack of resolution used for IBL Light Emission (keeping Quality U / Quality V below 7)?
The second workaround makes the IBL node emit light again but with poor results and even further increased render times.

However, I'm curious about what chuckie7413 mentioned.
Following the linked thread on the mentalimages forum I assume the new IBL solution is not really implemented in Maya yet?
Or is there a viable alternative to using IBL Light Emission, with at least comparable results and render speeds, now?

cavemen
08-13-2010, 05:37 AM
should we start a thread with the Heading as Maya 2011 post Hotfix3 bugs ? I guess that will help us all to know all the bugs that still exists in the latest " updated "version of maya cause even I have a couple of potential bugs to share..

sentry66
08-13-2010, 07:32 AM
sadly this was the very first bug I noticed with maya 2011. I loaded up a maya 2009 scene and did a render to compare the rendering time. I was expecting a faster and possibly even nicer looking render, but was horrified by a 6x longer rendering time and my IBL node no longer emitted light - what the hell?? People pay money for this update?

Even after 3 hot fixes...still nothing

so Maya 2011 = not a solution

All the slower interface and hypershade stuff made the decision that much easier.

This is why I don't buy annual support

chuckie7413
08-16-2010, 12:48 PM
However, I'm curious about what chuckie7413 mentioned.
Following the linked thread on the mentalimages forum I assume the new IBL solution is not really implemented in Maya yet?
Or is there a viable alternative to using IBL Light Emission, with at least comparable results and render speeds, now?

The new IBL is not implemented in maya in the fact that it is not built into the UI. You can unlock it with string options.

The thread should mention what string options those are. For more info on it you can also view the help files in the mental ray section. - mental ray - mental ray for Maya reference - Image-based Lighting

Best,

Rich

Eshta
08-16-2010, 05:05 PM
The new IBL is not implemented in maya in the fact that it is not built into the UI. You can unlock it with string options.

The thread should mention what string options those are. For more info on it you can also view the help files in the mental ray section. - mental ray - mental ray for Maya reference - Image-based Lighting

Best,

Rich

Isn't this the same as in Maya station

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"

chuckie7413
08-16-2010, 05:25 PM
correct :-)

mduvekot
08-16-2010, 07:29 PM
should we start a thread with the Heading as Maya 2011 post Hotfix3 bugs ? I guess that will help us all to know all the bugs that still exists in the latest " updated "version of maya cause even I have a couple of potential bugs to share..

You can find such a list at http://bugs.thnkr.com

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