Render settings changing after adding a sampler info node

[Justinoman]

I sent some renders to the farm and they where rendering at substantially higher render times. On reviewing the elements in nuke I see that the frames are very crisp and looks like the noise threshold is lower or GI settings are higher. When I look at the file it looks like the exact same settings that I had for a previous version that was rendering fine.

I thought it was some bug or error that might have been introduced so I rolled back until I found a file that was not broken. I saw that in this particular file I was in the middle of adding some AOVs that included some piont camera and piont world stuff. I did a render test and the file was rendering as expected.

I retained this good file and continued on with the AOV setup that was not finished. I added a sampler info node so I could set up an AOV. Right away I did a render test. Render times shot up and render was crisp and not noisy again. Then I deleted the sampler info and did a second render test. Rendered fast again and normal noise again.

So adding the sampler info node somehow is changing the way vray renders. with the sampler info node included in the file I can literally dial the DMC thresh to .8 and it renders as if it was set to .010 !!!

[vlado]

Make sure the "consider for AA" option is disabled for your ExtraTex render elements. Otherwise, V-Ray will try to antialias your world position pass...

Best regards,
Vlado

[Justinoman]

Yes I understand that. This is a bug I am pretty sure. It has nothign to do with anti-aliasing. The main beauty is getting effected just by adding a sampler info into the scene. The render times of the entire scene change when I add that node to an extra tex. Regardless of AA the render times and quality shoot up exponetially. But I do understand that world passes need to be Aliased to work correctly.

Speaking of that, only when I use Fixed rate does the AA go away. I have been required to break out a seperate pass with fixed rate used just so I can get a pass with no AA. But that is a side issue to this bug issue.

[vlado]

I don't think there's any bug... But then again maybe I did not understand what is your particular set up. If I keep the "consider for AA" option OFF for my extatex element where I connect a samplerInfo node, then there is no difference in the AA, colors or render times of the image whatsoever. However just to be sure, it would be best to post a scene so that I can check it out.

Best regards,
Vlado

[Justinoman]

Yes you are not getting what I am saying. There is a bug in my scene for sure. Me and two other vray artist have pored over my scene and I've located the issue exactly.

Let me re-iterate what is happening.

1. I have several beauty passes being rendered. One in particular is called "towerMain" It renders at 10 minutes average.
2. I add a sampler info node into the scene to set up an AOV. (pop it in an extra tex) No other adjustments to scene.
3. Now that same beauty render takes 14hrs to complete! But it is beautifully un-noisy.
4. just hitting delete on the sampler info node and the "towerMain" layer once again renders at 10 minutes.

How is that not a bug? Let me see if I can sent you a test file soon.

Justin

[vlado]

The ExtraTex element has an option "Consider for AA". In your scene, for the render element that you are connecting the samplerInfo node to, what is the value of that attribute - on or off?

Best regards,
Vlado

[vlado]

I mean this option:



It should be OFF (the default is on, so you have to explicitly go and disable it).

Best regards,
Vlado

[Justinoman]

Yes that button would be checked off in my world AOVs, but since the render times go through the roof when I add a sampler info node to the scene, I am not even adding any AOVs.

[Justinoman]

I'll try and wrap something up if I can this weekend. Thank you so much for taking the time to respond Vlado!

[vlado]

Ok then, will wait for the scene.

Best regards,
Vlado

[Justinoman]

Side question. Is it possible to put the 3 channel alpha to a separate render element? (The exr converter collapses the colored alpha to black and white and so GI shadows don't comp right.)


getting a scene to you maybe next week when I get a free moment.

[vlado]

For the moment no, but we can add a command-line option for this - let me know if you need it urgently.

Best regards,
Vlado

[Justinoman]

I worked around it, but it could be handy if it was a element selection. I am working on getting you a scene for the other issue but it might not be for a couple weeks. We are slammed right now.

For the moment no, but we can add a command-line option for this - let me know if you need it urgently.

Best regards,
Vlado

[vlado]

Ok then; no worries - whenever you get a chance

Best regards,
Vlado