Consistent Lighting Elements // Vray Lights "Affect Reflection/Specular" does not change to old behaviour

[Mr.Hoo]

Hi,

we want to switch to the old behavior of composing the AOVs by turning off Consistent Lighting Elements.
Everything works fine besides: if you want to control the lights contribution by e.g. turning off "Affect Reflections". This seems to not work at all, compared to "Before Vray Next".

I attached a scene below

Maya 2018.3
V-Ray Next for Maya, update 2.2 version 4.30.02, revision 29994 from Apr 9 2020



Is it maybe already fixed or is it intended do behave so? Or is it a bug ?



cheers
Dominik

[Mr.Hoo]

Anyone any idea?

[SonyBoy]

Are you saying toggling those attrs. off is having no effect? It works fine for me here -- Maya 2020.1 and Vray Next 4.30.01.

That's an older version of Vray than yours so I suppose it's possible a bug has been introduced......

[Mr.Hoo]

Are you saying toggling those attrs. off is having no effect? It works fine for me here -- Maya 2020.1 and Vray Next 4.30.01.

That's an older version of Vray than yours so I suppose it's possible a bug has been introduced......

Hi, yeah, exactly: when I turn off "Affect Reflections" nothing changes.
Maybe you are right - ill try a newer build.

[Mr.Hoo]

Hi,

tested with:
[2020/Jul/31|08:45:08] V-Ray: V-Ray Next for Maya, update 2.3 version 4.30.03, revision 30237 from Jul 24 2020, 02:00:57

No luck. Still the same

[SonyBoy]

I think it has always worked this way, i.e. you will need to also turn off Affects Specular in order to remove reflections. I agree this doesn't always make sense.

[Mr.Hoo]

I think it has always worked this way, i.e. you will need to also turn off Affects Specular in order to remove reflections. I agree this doesn't always make sense.

Hi,

no, this behavior is intended with consistent lighting elements since Vray Next.
But can be switched to the old behavior by turning that off.

You can notice in the specular / reflection element, how indirect and direct reflections are handled either way.

With the new way (which is state of the art) from the point on you bring your glossiness away from 1.0, ireflections get treatened as indirect and go to the specular AOV.

But the button "Affect Reflections" seems to not respect the "consistent lighting elements" toggle.
Which could be a bug.

[Mr.Hoo]

Hi,

any ideas from Chaosgroup ??

[yolov]

Hey, sorry for the delay.

You have correctly noticed that the Specular render element holds the direct reflections and Reflection holds the indirect reflections in the scene. It has nothing to do with how glossy the material is (be it 1.0 or below 1.0). Your observation is correct and I believe that this was introduced with the Consistent Elements option in 4.30.01.

Can you tell me in a bit more detail what you need to achieve in your setup?

[Mr.Hoo]

Hi Alex,

we were always happy to be able to disable unwanted reflections in certain parts of the geometry, if it was not possible to do it in a "real way". e.g. Car Beauty Renderings.
That was in the days of Vray 3.6. No it seems not beeing possible, with consistent lighting elements on. BUT, even if we turn them off, "Afect Reflections" does not work. We still have reflections in the specular RE.
that was not the way in former times.

Hope that makes sense

cheers

[yolov]

Can you give me a specific example of what the setup is and what it achieves?
Is the goal to make a light completely not affect glossy reflections, but still affect non-glossy reflections?
Or is the goal to separate out glossy and non-glossy direct and indirect reflections to grade them in post?
Any scenes, example comps, illustrations, images or other will be very helpful.

[Mr.Hoo]

Hi Alex,

I am sorry for being not precise enough.
I attached gifs and scenes for you.
My second gif is really bad quality, because of the file size restrictions, but I think you'll get the point


LEFT: Vray_3.6.gif: This is the desired behavior (what we want to achieve) for Vray Next (but in this example it is done in Vray 3.6)
RIGHT: Vray_4.3.gif: This happens currently in Vray Next - but we want to have same behavior as seen in the previous example

Hope everything makes sense now

cheers
Dominik

[yolov]

Do you need to render in this setup directly? Alternatively, if you can separate the different light contributions in post and remove the unwanted ones as needed in post - would that be acceptable?

[Mr.Hoo]

Hi,

yes I think it could be possible.
We were only used to be able to get rid of the reflections, as it was handled by 3.6 and below. Now the "correct" interpretation and handling of reflections just involves new thinking.

cheers
Dominik

[ali_cgi]

Having a similar thing.. Vray 5 - Maya 2020. Classic blend material carpaint. Vray Material for base and a second for clearcoat. As soon as I add a small amount of glossiness into the shader the vray lights affect reflections no longer works properly.

This I am hoping is a bug! As without this control I will not be able to use Vray 5 on automotive jobs... well any job that requires this specular vs reflection separation

I posted this before I found this thread.

https://forums.chaosgroup.com/forum/...rangley-vray-5