Grains in render

[romanm]

I got problem with render, I have this grains in the image.

 

 

I got 1 V-Ray light above the teapod.

 

Multiplier 3

Subdivs 50

Edited February 4, 2017 by romanm
adding picture

[romanm]

Update:

 

 

So I experimented with Light Multiplier, Subdivs and other thing which can doing that noise and I found some good one variation.

But if I use that setting on just little bit of render, it looks good, but if I render whole image, noise appear. I don't unerstand that.

On the picture, first I rendered whole image, after that I rendered only that red square but with same setting.

Why is doing that?

[Stephen Thomas]

Post a screenshot of your render settings if you want more feedback. Otherwise we can only guess. Are you using progressive image sampler?

[romanm]

I understand why is noise in my render, I am just beginner and I have to more experiment with settings.

But what I don't understand is, why is crop render diferrent from whole render.

Shouldn't it be same?

[Francisco Penaloza]

Post a screenshot of your render settings if you want more feedback. Otherwise we can only guess. Are you using progressive image sampler?

we need settings.

 

why is crop render diferrent from whole render.

Shouldn't it be same?

No necessarily.

[John Dollus]

progressive method decreases noise with more time. Smaller area requires less time to eliminate noise.

[romanm]

[Francisco Penaloza]

 

as I thought and mentioned by John already, you are using progressive rendering configured to stop at 1 minute ( this is default).

So this meant that independent of your scene after one minute the render will stop no matter if the scene is 'clean' or not.

 

To get a more clean image you need to let it render longer or setup a larger number of passes.

You could switch to bucket mode to get a 'cleaner' result, but then you need to adjust your samples as need it.

 

If you are using bucket mode then region render should represent final quality no matter what, obviously render time will be longer.

thievery is well explained on VRay manual.

[Stephen Thomas]

As I thought

[romanm]

Thank you guys. It works now

 

But.....

 

 

It's too much now

What should I do? Set less passes? I don't know what is it and where is it.

 

I am rendering on very slow ntb (2x2.4Ghz / 4GB RAM) so I undestand that why it takes long but 70 hours 1 image, I think it isn't good.

 

 

BTW: When I had in settings that 1 minute, as you can see in render history, renders worked longer time than 1min anyway.

[Francisco Penaloza]

Rendering is always a trade of Time Vs Quality, if you are in a slow machine it really won't help.

 

You can adjust number of Max subdivs right in the same area were you change time of rendering.

 

By default VRay is using Brute force as first bounce, you can Try Irradiance and Light cache, that will render faster not questions.

You could switch to bucket mode and Irr with LC, then you have more options to optimize your rendering time.

[romanm]

Ok thank you. I am happy that noise is fixed. I will experiment with render setting now to find any good compromise.

 

I don't need any perfect render I just want to see what I created.

 

I will try that things what you said.

 

So thank you guys. Problem fixed.

[maichi]

TKs so much