NormalMap issue with refraction

[bardo]

Hi,
as attached you can see something I consider quite strange, if not a bug.
I've a shop with a wall with horizontal stripes.
The material is a VrayMat with a normalMap as you can see in the image.
The windows of the shop has a glass pane that visually is in front of the wall. (to debug the scene I've moved down the glass so I can see the difference )

As you can see, if I use the refraction for trasnsparency the horizontal stripes seems scaled.
I thought to a lens effect but also with IOR to 1.0 it's the same.
If I use opacity everything is fine.

Am I wrong with something or there is some issue by Vray?

[vladimir_krastev]

Hi your resolution and quality are pretty low. Are you using denoiser? Could you render the images in higher resolution and better quality? are you talking about the grey wall or the white wall?

[bardo]

Hi your resolution and quality are pretty low. Are you using denoiser? Could you render the images in higher resolution and better quality? are you talking about the grey wall or the white wall?

I've rendered doubling the resolution. It seeme better than before but as you can see the stripes on the white wall still be dfiferent when using refract (both IOR 1.6 and 1.0) compared to opacity.
I don't use denoiser.

[vladimir_krastev]

I see what you mean. I'd say try different settings. For instance higher min subdivs and/or higher trace depth in the material refraction. It is best if we could review the scene.

[bardo]

I see what you mean. I'd say try different settings. For instance higher min subdivs and/or higher trace depth in the material refraction. It is best if we could review the scene.

I've a link where you can download but I'd like to share just with you.
I've tried to create a PM but with no luck, it said me I can't open the conversation.
Could you give me another contact point?

[vladimir_krastev]

Hi you could share the scene through our support contact form.
Add a link to this thread in your message when you submit it.

[bardo]

Hi you could share the scene through our support contact form.
Add a link to this thread in your message when you submit it.

Ok, I've written a support request

[bardo]

Hi you could share the scene through our support contact form.
Add a link to this thread in your message when you submit it.

Thank you for helping me with this issue.

Sharing with the others, the solution is to set the blur parameter to the min (0.001).
Thank you very much

[vladimir_krastev]

The wall is relatively far away from the camera and the bump map that was used is of poor quality. This combined with the glass panel in front of the camera causes these effects on the wall.
I haven't tried really high sampler settings - most probably will work but will slow down the frame a lot. With medium sampler settings is a bit better but still not perfect. By reducing the blur of the bitmap we can have the wall rendering with more detailed bump and still keep the sampler settings low.