Glass & Background Color Issue

[leejk]

Hi,

I have run into a problem that I cannot figure out. In the attached images, in order to get the shadow of the cylinder that is on the opposite side of the glass to show up in the alpha channel, I must turn on the setting shown in VRay Properties for the matte object. But when I do, instead of the environment background color of white showing thru the matte object, it instead turns black. It only does this when looking thru the glass material; if I move the camera outside, the floor is white like the background as expected. While this is not really a problem for post, I'd still like to know why this happens.

thx

[tashko.zashev]

Hi,

I suspect that there is a bug causing this. Could you post a screenshot of the material you are using for the glass object?
Do use have set Affect channels to All channels? If yes, try to switch back to Color only and run a test.

[leejk]

Hello,

Yes, on the glass material I have Affect All Channels set to all channels. If I switch the refraction setting on the glass material to color only as you suggested, the black goes away but then there is no alpha present for objects behind the glass. I think there are possibly 2 bugs present here.

For this problem I turned the option "Matte for refl/refr" in the Matte properties off to get rid of the black color problem mentioned in the beginning. Whenever the floor plane is turned into a matte object, it will no render the environment background color directly thru it as is shown in glass3.jpg when viewing the floor plane thru the glass. In this one I did a region render with the center glass pane hidden. Instead of the floor being transparent and allowing the background color to pass thru, it turns grey instead. Is this another bug?

[tashko.zashev]

Thanks for the update.

There is a bug related to the Affect all channels and matte for refl/refr rays. I'm going to log this in our system right away.
About the second problem, how you hide the glass pane? Could you attach a simple scene for this?

[leejk]

Thanks for logging. If you remember please report back when it's fixed in a nightly build and I'll test it out; as for me this has always been a problem spot in my production work even with 2.0 I think.

To hide the center glass I just turned it off. Attached is a test scene. Can you speculate what is causing the grey floor when viewed thru the glass? That is not realistic behavior.

thx

[tashko.zashev]

Hi, thanks for attaching the scene.
Actually there is no issue here, matte surface will not give you the environment color/texture without using the option "Matte for refl/refr rays". This option should be turned On in order to get the result you expect, but unfortunately the alpha will not be useful until we fix the first issue.

In the meantime you can try to render the scene on two passes. One with Affect channels to Color only to get the Beauty, and second on "All channels" (using render selected feature to include only the glass objects) to get the alpha.

[leejk]

I need to render an animation, and I'd rather not have to do multiple passes as that gets complicated. I can wait a bit for the fix tho if it comes soon.

[tashko.zashev]

I need to render an animation, and I'd rather not have to do multiple passes as that gets complicated. I can wait a bit for the fix tho if it comes soon.

We will inform you as soon as this bug is fixed.

[leejk]

Hi,

Was this fixed in the release just made available? The email that went out has links to the release notes, which are not viewable... I get a forbidden error.

thx

[svetlozar.draganov]

We are sorry to inform you but the bug hasn't been fixed yet, we will update this thread when that happens.
According to the forbidden error link - would you please try to open it again and if it doesn't work please inform us from which country you are trying to access it and what is the exact link.

[leejk]

Hello,

I'm in the US, and here is the link I was emailed: https://newsletters.chaosgroup.com/r...6361742e636f6d

thx

[tashko.zashev]

Hello,

I'm in the US, and here is the link I was emailed: https://newsletters.chaosgroup.com/r...6361742e636f6d

thx

Our IT guys have checked the file on all servers and everything seems to be fine. Would it be possible to try with a different browser ? If you still have problems, please send is a screenshot or a screencast of the error you got to our support mail (support@chaosgroup.com)

[leejk]

Both browsers Safari & Chrome report the same error:

[tashko.zashev]

Thank you for attaching a screenshot.
Could you please try to open the following address:
http://www.chaosgroup.com or http://docs.chaosgroup.com using the full address path.
And this is the direct link to the PDF http://www.chaosgroup.com/public_ima...0.08_Build.pdf

If those links works fine at your side, most probably there is a problem in the redirection path used in the news latter.

Regarding the bug you have reported with black matte render when "matte for reflection refraction rays" is On, we have some progress on it. In our internal builds this is partially fixed, but there is another issue connected to render elements, which we still need find a way to fix. So when we are sure that this issue is fully fixed we will let you know.

Update: actually there was an error in the redirection paths only for the US area and our IT team managed to fix it.

[leejk]

The redirect is now working!

Thanks for the bug update... I will keep a watch for updates.

thx