Refraction peculiar noise

[flaviuscristea]

Hi there!

I am currently testing out Vray-GPU for the last 2 days as I would like to switch from CPU Rendering (Currently rendering with Corona,) because it is really slow with foam and refraction.
However I came across a weird problem. Please see attached -> both images are 1 minute render. One has refraction ON, the other has it OFF

When I turn on refraction in the Vray Material some really weird noise starts to appear and it takes a really, really long time to clean it. This kind of noise does NOT appear when rendering on the CPU.

I currently have a 1060GTX 6GB, but I am planning to upgrade soon, hopefully we'll clear out this refraction issue in the meantime.

Thanks all in advance!

[hermit.crab]

Best you send the scene to support@chaosgroup.com so we can take a look. Mention this thread in the e-mail along with your V-Ray and host platform versions.

[gaara the nightmare]

sorry to bring this thread back, but I just find out that I have the same problem.

I think I found where this weird noise in refractive object is coming from.

Did you use the "Full lights evaluation" settings in the settings tab of VRay GPU?

I've seen that when I'm using the setting "adaptive lights" the moiré noise disappear. However, I often have artifacts problem with adaptive light, that's why I use most of the time the setting "Full lights evaluation"

hermit.crab is it possible to fix those problems ?

Thanks !

[hermit.crab]

gaara the nightmare Could you send the scene via the contact form so we can do some testing? Mention me and include a link to this thread. Otherwise, most of the adaptive lights artifact issues are already fixed; you may use them as a workaround for now.

[gaara the nightmare]

Hi, hermit.crab ,

I continued my research and I found out that the problem involves more factors than I previously thought.

It is visible while :
- using VRay GPU
- multiple objects having both VrayEdgesTex in the bump slot intersect each other (f.e. ground with water)
- "Affect shadow" unchecked in the refractive material
- more visible in bucket rendering
- using "Full Lights Evaluation" in the setting tab of VRay

I prepared a scene and sent it to to support few minutes ago. Let's see if it can be fixed

Thanks for the info about adaptive lights setting, I'll check it out !

[hermit.crab]

Something might have gone wrong since we have not yet received the scene. Could you please send it using the contact form again?

[gaara the nightmare]

There's maybe a communication issue somewhere because I've received an email today about the scene (ticket number 2451), saying that there has been a lot of tests on it and that there was indeed a problem somewhere. That I should use VRay denoiser to clean the moiré problem, which is not really the answer I was looking for.

As I explained in my previous comments using the "adaptive lights" setting will get rid of the noise

I just want to help to find the origin of the problem and see if that can be solved by the technical team. This way nobody will have this problem in the future

[hermit.crab]

Indeed, there was an internal communication issue. Excuse us for that. As you know, we have logged the issue (internal bug-tracker id: VGPU-5521) for developer investigation. You can work around the issue by turning the refractive material's "Affect Shadows" option, using the denoiser, or simply the Adaptive lights.