No GI but getting Crawling Noise

[Infrared digital]

Hi

I am rendering an animation with moving objects but not using GI - unfortunately I am getting crawling noise. Ordinarily I would do the pre-render and the animation-render with moving objects but without GI I don't think that it's necessary.

How would I get rid of the crawling noise ?

Thanks

N

[Neilg]

It's either reflection samples, light samples, or low AA - nobody can tell from what you said without an example. Try raising all 3 in turn, but I accept no responsibility for your render times if you increase the wrong one too much.

[Svetlozar Draganov]

You can easily find out where the noise come from with Render Elements.

Reflection Render elements - shows noise from Reflection Subdivisions
Specular RE - shows the noise from Light Subdivisions
With SampleRate RE you can determine how much samples are used per camera rays and the noise will be visible in the Beauty pass.

The solution is very simple - just increase the subdivisions in Materials if you have noise in the Reflection RE , in Lights if you have noise in the Specular RE.
If Sampler Rate Element is mostly blue - you have to decrease Threshold value in Image Sampler - if it is mostly in Red you have to increase Max Subdivisions.

[Infrared digital]

I appreciate your comments !

Do you mean VRay Reflection and VRay Specular render elements ?

[joconnell]

Yes he does. I'd also be inclined to add in the raw lighting element.

[Infrared digital]

Ok thanks, I will do a test render over the weekend.

Incidentially, below is a link to the previous version of the clip - the noise I am talking about is most noticeable just before the white element stops rotating from about 9 to 12 seconds;

http://vimeo.com/62856198

[Svetlozar Draganov]

From what I can see the amount of noise is not too much, so a little higher subdivisions should fix it.
The easiest way do do it is to take 5-10 frames with most noticeable noise, add Render Elements that we've discussed earlier , determine from where the noise comes from, increase subdivisions and do another test render on these 5-10 frames - then compare the result before and after. Few iterations should be enough in order to find the best settings - you can also use region-render option instead of rendering the whole frame.

[Neilg]

Ok thanks, I will do a test render over the weekend.
Incidentially, below is a link to the previous version of the clip - the noise I am talking about is most noticeable just before the white element stops rotating from about 9 to 12 seconds;
http://vimeo.com/62856198

I'd guess at light subdivisions. The red part looks like it could do with sub pixel mapping turned on too.