VraySky and exposure

[AlexP]

Hello, havent used vraysun/sky for a little while. Started to use on a new project today.
The light emitting from the sky doesn't change when I change the camera exposure.
Is this actually correct and Ive missed some fundamental change or is this a bug?
Or am I going insane?

This is on 3.60.01

Test below, seems really odd ?? one of these is 5 EV one is 10 EV, even I go to -100 EV its the same.

Should note that, if the camera is pointing towards the sky, the pixel values of the sky DO change, its just the light emitting that does not.

Am I an idiot and missing something obvious?

[glorybound]

You have to enable it and you have to start a render first, go back to it and apply it to a camera.

[AlexP]

It is enabled already.
Exposure is affecting everything else in the scene, just not the light contribution from the sky

[notamondayfan]

Turn the sun and sky off, and re-render. It should be completely black. If not, there's another source of illumination, like a light, background, or other override.

[AlexP]

Yep confirmed.
Just to be clear this is a fresh scene, with only a box, a camera and a vraysky

[AlexP]

In fact this is the scene

[^Lele^]

Did you try with V-Ray exposure, rather than max/mR's one?

[AlexP]

If you mean this one - then yes - no effect

[Martin.Minev]

Hi,

We have made some tests using your scene. We have a similar issue reported into our bug tracker. When V-Ray Sky ( or other texture ) used in environment, I assume there is a limit for the GI rays using higher exposure values ( higher ISO ).
As a workaround you can disable the Max ray intensity. http://ftp.chaosgroup.com/support/sc...0_16-16-28.jpg. We will notify you, when there is any progress with the issue.

[AlexP]

Thankyou Martin
Thanks for putting me out of my misery
At least I know Im not going mad.

I guess disabling the MRI introduces too many other potential problems, in which case it's better to just shove the sky in a domelight.

[dlparisi]

Hi,

We have made some tests using your scene. We have a similar issue reported into our bug tracker. When V-Ray Sky ( or other texture ) used in environment, I assume there is a limit for the GI rays using higher exposure values ( higher ISO ).
As a workaround you can disable the Max ray intensity. http://ftp.chaosgroup.com/support/sc...0_16-16-28.jpg. We will notify you, when there is any progress with the issue.

You can also just increase the max ray intensity to a higher value as well (~50-100). Additionally, it seems a bit odd that you had specified the vraysky to have an intensity multiplier of around 44 in your sample file which was further impacting the limit on the ray intensity. Unchecking the "specify Sun Node" resets the sun system back to normal and when used with EV of 5 and 10 you definitely will notice a difference even with the max ray set to 20 . There is still a bug that if you go too low with the EV (say below 5) the scene doesn't change and this is where adjusting the Max ray intensity will come into play.

[AlexP]

To be honest I was just trying to get something to happen, so was trying all sorts of crazy numbers. In the production scene, the sky is at a sensible 1

[dlparisi]

To be honest I was just trying to get something to happen, so was trying all sorts of crazy numbers. In the production scene, the sky is at a sensible 1

It's weird then that it didn't work for you at 1. It works just fine for me with EV's of 5 or 10.

[AlexP]

It's weird then that it didn't work for you at 1. It works just fine for me with EV's of 5 or 10.

Possibly down to the high iso numbers as Martin mentions, as I had DOF on with probably a low F number.
I'll do an experiment or two in the main scene.