IPR Viewport and double gamma

[snivlem]

Hi,

Anyone else notice sometimes you go change the viewport from Viewport 2.0 to V-Ray IPR and the gamma suddenly doubles up?


Default maya state (viewport 2.0)


Switch to V-Ray IPR - note gamma is now somehow doubled


Go back to Viewport 2.0 - gamma is burned in now for the rest of the maya session. It should be the exactly the same as the first screenshot.

(PS I do not use Linear workflow checkbox, everything is done with Maya rules).

The regular V-Ray render is ok, it just seems to be the viewport that is affected. Using latest build and the bug is still there.

[snivlem]

Hi this is still a problem with V-Ray. Is the bug in the tracking system?

[tashko.zashev]

Hi,

It doesn't look like a known issue. Do use the Maya default color management or you have any customizations? Would it be possible to send us a sample scene to test it here?

[snivlem]

I'm surprised this isn't a known issue. It literally happens all the time since last year with every build.

I can reproduce with a simple cube on a blank scene.

All prefs are default and colour management is set to default rules. I'll send you a link to the screencast.

[tashko.zashev]

I'll send you a link to the screencast.

Can't reproduce this behavior on several machines in our office so I would like to have a scene to test with, even if it's a very simple one. Thanks!

[snivlem]

Wow, that is really strange. This will be very difficult to fix then. I always start maya with default prefs and in this case it was Maya 2017 update 3 default colour management prefs.

I've attached the scene from the screencast although I don't think it will be of much help.... When I open this scene in Maya for the second time it works as expected and the double gamma issue never appears.

gamma.zip

As the screencast shows, the issue only appears on blank scenes or on an old vray 2.x or 3.x scene.

I run a Quadro K2200 if that is of any help. I've seen the bug almost for a year on two different computers though.

[tashko.zashev]

Thank you for the file.

I can't reproduce the view-port darkening even with the scene attached " gamma.zip", but found a potential issue with the Viewport settings that may help to solve it in your environment.
Can you try to change the Transparency Algorithm property >>

[snivlem]

I've tried this, but it's definitely VRay IPR that causes the issue. Alpha Cut was only introduced to Maya in the last few weeks with Update 3 but this issue has been around since a year. As I mention, it's a weird bug.

Maybe try with the Gamma set to 2.2 and mode to "Don't effect colors, only adaptation"?

[snivlem]

(edit: can't delete post)

[snivlem]

(sorry, can't delete this post).

[Zdravko.Keremidchiev]

Do you work on Windows 10 as mentioned in your signature? Also do you have earlier Maya installation where you can test this issue?

[snivlem]

Yes, w10 (build 14393.953) if it matters.

The same issue was appearing under Maya 2016 as well.

[Zdravko.Keremidchiev]

Its difficult to assist you if we can not reproduce the issue in our environment. Could you please try to use different render engine for Viewport 2.0

[snivlem]

It's not VP2 though. There is an issue with the IPR.

With the default settings (NOTHING touched), here is a render to best illustrate there is a difference with colour management between VRay IPR and the offline renderer.



This is a simple scene with all default VRayMtl shaders. Notice the blacks are different because the IPR colour workflow is doubling up.
I have no idea with why this isn't repro on the other end as everything is default.

Once VRay IPR breaks the colour workflow, then VP2 has the double gamma issue. VP2 issue is the last issue in the chain.

[yolov]

We can't really control that for the moment, Maya applies its color management on top. Have a look here: https://docs.chaosgroup.com/display/...entandV-RayIPR
You can disable the color management and rely on our sRGB, or just disable to view transform sRGB that is applied by the Maya color management to the viewport.