Lot of Noise in High+ Quality Render

[manishpaul_simon]

Hi,

I was trying out this sectional perspective render with the rectangular lights in the ceiling. I have hidden with them with the help of the section plane and with "affect lights" turned off.

I'm not sure why it's producing this much noise. I'm using only one set of rectangular lights in this scene.

And an infinite plane so that the light gets to bounce off a surface.

Is there any way to get a crisper render and avoid all that dirt and noise in the image?

Thanks

Here's the link to the sketchup file
https://drive.google.com/file/d/1Dnv...ew?usp=sharing

[nikoleta.garkova]

Hi manishpaul_simon,

Thank you for providing the project files. After running a test it appears that you are in Source:LightMix and there have been some adjustments made to the lights - i.e., the rectangle light is with much higher intensity and different color mode, far more drastic compared to the original RGB. The RGB itself is actually very, very dark, as shown in the attached recording.

If you want to use those values, best would be to push the LightMix adjustments with the 'To Scene' option (this will place the adjustments directly in the project). You will get much clearer results when you render it out, as demonstrated here.

To read more about LightMix, please visit: https://www.chaosgroup.com/blog/reli...rks-in-v-ray-5

[manishpaul_simon]

Thanks a lot Nikoleta.
I'll test that out your tips and keep you posted.

[konstantin_chaos]

Hi manishpaul_simon,

What Nikoleta described is exactly right.
I just want to give you better context by explaining why this is happening:

V-Ray has some internal optimizations when sampling the image that you have no control over.
One of them makes sure that dark areas of the image are sampled less - this avoids slowdowns in areas that you don't actually see clearly.
The majority of your set falls into that category - V-Ray is under the impression that everything is dark, you'll not see it at the end and hence it avoids high quality sampling (even though your settings suggest otherwise).
The fact that you're exposing the image in the VFB is not something that the sampler knows about.
That is why, applying the light intensities from the VFB to the scene, should resolve the issue - the V-Ray image sampler will basically see the same image you're looking at and will give you the High quality you've requested.

Hope that makes sense,
Konstantin