GPU rendering of cascade of water is producing these artifacts???

[JezUK]

I am GPU rendering a garden scene and only when I added my water cascading down a rockery is there this strange artifacts occurring in my render.

Please can someone explain, I tried reducing the noise from 0.01 to 0.005 but that just made things worse.

These artifacts only occur over the water of the cascade. They do not occur anywhere else in the image, so I am assuming it is a water/phoenix issue?

Please can someone or Chaos themselves advise?

Thank you.

[georgi.zhekov]

Hey,

These look like V-Ray Denoiser artifacts that are showing when there are not enough samples in the base render.
Do you have V-Ray denoiser enabled? How about if you disable it.

If you have a V-Ray sun in the scene , does it help if you turn on the invisible checkbox?

[JezUK]

Hi Georgi,

Thank you for your quick response.

Yes, I do have Denoiser and it is very useful

I'll retry quickly now and report back.

No, I don't have a V-Ray Sun, I use the wonderful HDRI's in Cosmos. Any ideas ?

Many thanks.



***** Update *****

Yes, it's the Denoiser - if I disable it, those go away.

(but I'd like the denoiser if possible).

However, whilst those artefacts do indeed disappear, I am left with what I believe are called fireflies (very white pixels) scattered over the water.

Again, any ideas

Many thanks.

********************

[JezUK]

Here is a screen grab with Denoiser switched off.

[georgi.zhekov]

Ah in this case - check these threads:

https://forums.chaos.com/forum/v-ray...in-reflections

https://forums.chaos.com/forum/v-ray...-best-practice

Hope this helps!

[JezUK]

Thanks Georgi, I re-rendered with making HDRI invisible and I still get these marks (I've screen grab whilst zoomed in a lot more).

I'll go and read up on your threads next.

Many thanks.

[JezUK]

I must say that using the "Intel Open Image Denoise" option for Denoiser improved things a lot

Thank you