Uneven Grain patterns

[karina_cunha]

Hi,

I recently started using V-ray 5 and have been noticing an uneven grain patterns in dof and motion blur areas that its been a bit difficult to deal with. I usually use neat video to reduce the ammount of noise on my renders and due that uneven grains i'm having a hard time to clean up my renders.
I used to use Vray next and had no problems with that. I'm probably doing something wrong and i'm wondering if you guys can give me an input. The settings i'm using is the default. 1/24 noise threshold 0.06. I also notice those grains seems to be a fixed patten which makes even harder to clean (not using lock pattern option). Let me know if you have any inputs how to deal with that on vray 5. I'm posting some images from vray next and vray 5 to compare the grain and looks like vray 5 have stronges grain contrast between different areas.

Thank you!

[vladimir_krastev]

Hi it seems to me that the V-Ray 5 image just has more noise overall. What are we looking at - is this the VRayDiffuseFilter?

[karina_cunha]

Hey Vladimir, Yeah that is the difuse filter. I think the problem is indeed the fixed pattern and not the ammout of grain. I'm NOT using the "LOCK NOISE PATTERN" feature but it seems that Vray 5 has a locked pattern running by default in the engine. I have noticed that in multiple scenes and have been struggling with it making me think move back to vray next. I just have one project going on that its all shaded and lighted in Vray 5. so looks like there is no way back for this one. I was wondering if you guys have give me a light on how to fix that. I rendered a very low sampling scene so I could just see the noise patterns, run multiple tests with different samplings, tried also progressive, but seems vray is having different noise patterns, a float one and a locked one that happens at the same time Also its very clear when running a denoiser plugin such as Neat video or so. In this render I had a bokeh texture which makes the red channel really visible.
Let me know if you can give any inputs.

Thank you!
Pedro Conti

[karina_cunha]

I setup a simpler scene with a teapot one vray light, a vray camera with the teapot out of focus. so the issue appears very clearly.
2 patterns of grain. one locked and another one that is chaning everyframe. Im using the latest vray5 for max

[karina_cunha]

Looks like the issue is been caused by the blue noise sampling which seems to be hiden in the latest vray. I downgraded to vray 5.00 and disabled, seems to be perfect. I was wondering if I can disable it for the latest vray version which is the one i'm using for my project. The DMC sampler tab doesnt show up here in the latest.
Thanks!
Pedro Conti

[vlado]

The option is still there and can be disabled through MaxScript, but generally this is something that we can fix - will look into it.

Best regards,
Vlado

[karina_cunha]

Hey Vlado, thank you so much for looking into it. Cool yeah i really have no idea on maxscript hahah XD
Would be really awesome to stay in the lastest version and fix that. Having so much fun with the new features

[vladimir_krastev]

Hi I tested the scene with V-Ray 5.1 (blue noise on/off) , V-Ray 5.2 and V-Ray Next. You are correct - enabling the blue noise results in this unusual noise pattern that you are describing.

V-Ray 5.1 - blue noise enabled



V-Ray 5.1 - blue noise disabled



V-Ray Next



V-Ray 5.2



I also created a log in our system under VMAX-12004 for further investigation.

[karina_cunha]

Hey Vladimir,
Thank you so much. The script would be really helpfull for sure. It's something I was trying to figure out since january and I was wondering if I was doing something wrong or have missed anything new in the update.
I really appreciatte!
P.

[vlado]

Try typing the following into the MaxScript Listener:

renderers.current.dmc_useBlueNoiseOptimization=false

This should turn off the blue noise pattern.

Best regards,
Vlado

[karina_cunha]

Its really perfect Vlado. I will be running some renders overnight. Will let you know, but looks perfect.
Thank you!
P.

[karina_cunha]

Hey guys, Just updating here. The script is really perfect. I'm getting the results I'm used to have. so, thank you so much!
I really appreciate the quick solution!
P.