Glass Refraction with grayscale map - Problem

[Santiago_X64]

I'm working on a glass office wall project.
On some glass sheets, a silk-screen (sanded glass effect) is applied, which I managed through the reflect channel, Rglossiness, and glossiness of the vray material (glass).


My problem is that, when the screen printing is superimposed on other transparent glass, the calculation becomes very slow, the ram is saturated, goes into swap and writes to disk, and does not advance beyond that area, until the render fails.
I really tried everything and as a last test I raised the trasp. cutoff at 0.1 in global swithces, but nothing changes.

With the old vray versions I've never had problems like this, though the calculation was quite slow too.


I do not understand if it's a settings problem, or if something has changed with the new vray workflow.

Do you have any suggestion?

Thank you.

[Santiago_X64]

A little update for my problem...
I continued to do several tests without solving anything and the problem also occurs with glazed panels without screen printing ...


The problem is that when the calculation of the Bucket arrives in the area where two glazed panels are superimposed, the calculation becomes very slow and, the consumption of ram increases in an exaggerated way, vray writes to disk and can not go on.
The Bucket remain in that area for hours and hours without advancing.

I have calculated many similar images with this version of vray, also worked with glazed panels in the past, with different versions of vray, but I've never had any problems like this.

I can not understand what is the cause of this problem, if it is a wrong setting, or some incompatible element, or if some BUG.

My configuration:
Amd TR4 1950X 32gb ram + Vga Asus FGeforse 1060 GTX 6GB.
OS. Win10 pro
Software. Vray3.60.04 + Max design 2014

[yavor.rubenov]

Hello,

Best would be if you could send the scene to our support - they can check what is going on.

Apart from this - do you have any VRayDirt maps in this shader and also - what render elements do you have in the scene?

Best regards,
Yavor

[Santiago_X64]

Hello Yavor,
Thank you for your answer.

I attach an image where you can see the render elements (there are many) ...
For the vraydirtmap, I'm using only one in the render element Vrayextratex, in the texture channel, for ambient occlusion.

In any case, I sent the scene to your technical support, a few days ago.

Best Regards,
Filippo

[yavor.rubenov]

While support is checking it - could you try to lower the subdivs of the VRayDirt - 3 should be enough?

[Santiago_X64]

Ok.
I try with the subdivisions set to 3 and, I'll let you know.
Thank you,

[Santiago_X64]

I tried subdivids set to 3, but nothing changes.

[Svetlozar Draganov]

Sorry about the delayed reply from our side. I am working on your scene right now and here are my conclusions.
High Ram usage is actually not caused by glossy refractive shader, with our without it scene requires much more that 32GB to be calculated.
The slowdown however is indeed caused by the Refraction Glossiness but this is something expected.

I'm investigating now what's the reason behind the high Ram usage, we'll get back to you as soon as I found it.

[Svetlozar Draganov]

Can you try to switch Render Settings to defaults, then change the Image Sampler to Bucket and Primary GI to Irradiance Map with Medium preset?
Render times are much faster and the RAM usage is several times lower. There is some grainy noise here and there but I believe denoiser should be able to handle it without any issues.

Let me know if that works for you or not.

[Santiago_X64]

Hello Svetlozar.

Thank you for your answer and for your support.

Finally, i have fixed the problem.

This is the steps i used:
1 - reset vray render setting to default; (i tried this also before, without any result)
2 - Deleting all render elements;
3 - New setting for vray render - almost all by default (BF + LC); i can send the preset if you want
4 - Add all necessary render elements + somes Vraylightselect element - No add of vrayextratex element;
5 - Rendering calculation via deadline, VFB disable (only generate preview), write to file Vrimg; (i tried this also before, without any result)

The rendering with this settings is finished, wihout any problem of out of memory ram.
However, i really do not understand the cause of excessive use of ram for this simple scene...

Thank you!

[Svetlozar Draganov]

Thank for the feedback. The issue is indeed related somewhere in the render settings.
What you did is actually the same thing I did here, resetting render settings and starting from the defaults.
Default render settings are a very good starting point, very often they are perfect for final renderings.
I haven't check what exactly in the render settings caused that excessive RAM usage since I already figured out how to resolve the issue.

Regarding the scene complexity. Determining scene complexity and predicting Ram consumption is not a very easy task. It may seem that two scenes are very similar it terms of polygon count, features used in the scene but we can't be sure that those scene will occupy the same RAM amount. Sometimes even the same scene consumes very different amount of RAM if rendering from different cameras or with different resolution. In your scene for example the final resolution is quite high, at the beginning of my tests I used a smaller resolution and the RAM consumption wasn't that much. When the resolution increases a lot however the RAM usage rises exponentially and from 10-12GB it reaches to 100GB. This might look strange but it's something normal if you are using displacement, subdivisions or something else in your scene and you haven't optimized it for higher resolutions.

Let's consider this case as solved now if by any chance it occurs again contact us and we'll troubleshoot it further.