understanding VraySampleRate element

[fewlo]

Hi,



I have rendered this element, but I don't really know how I am to use the information it gives me? I am always interested in removing noise but also keeping render times down, as I mainly do animations, so can an understanding of this element help me out?

I love the flexibility of the different elements as I can see which element is causing the noise, and I'm sure this element will also aid my understanding of what is contributing to noise or high render times, but currently I don't know what I should be looking for!

Can someone please give me a bit of an explanation of how best to use this element?

Cheers, Mike

[themaxxer]

I love the flexibility of the different elements as I can see which element is causing the noise...

hello mike

may I ask you which elements you create to debug noise problems?

thanks a lot for your feedback.

best regards
themaxxer

[fewlo]

hi there,

as I mentioned, most of my experimenting is aimed at animation, but I usually find most of my noise is in the reflection element. As a rule I don't go much higher than 20 subdivs for materials, even fairly glossy ones, and I have dmc 2,4 clr threshold .005, with ref/refract max depth checked to 3.

sunlight subdivs 6, all vray lights store with irradiance map.

if the animation is 'dancing' due to noise I simply up dmc to 2,6 and this usually sorts it out...

I get predictable results and comfortable render times, and clients are always happy (well nearly always!) but I fully appreciate the renders could be crisper.

I've recently stopped using an aa filter and filter maps is also now turned off, which invariably adds more noise until I raise my dmc.... To better understand this (I think!) I started outputting the samplerate element, then hit the brick wall I am at now!

Whenever I deviate away from my 'comfortable' settings I get nicer results but much higher render times, which I cannot sustain on live projects at the minute..

Mike

[zeronove]

r u using 1.5 or 2.0?
from the img I say 1.5, if yes lighter blue means DMC is using its higher values, darker means lower values; you can try to change the clr threshold to see the ditribution changing.
hope it helps

[fewlo]

Hi Alessandro,

thanks for the reply, this now makes sense to me, I changed my clr thresh to .002 and could see that there were more light blue samples, I think meaning the sampler was working harder, hence a longer render time?

but problematic areas still occur, such as a tile floor... glossy .085 subdivs 24. I can get the noise to a workable amount by upping my dmc but I do not like the higher render times.

I kinda feel I'm changing things without fully grasping what I am changing! As I mentioned, I've taken off any filtering so that my render elements match the beauty pass, but that has given me more headaches and longer render times! Should I just accept these times, I'm averaging around 15-20mins for a 1024 x 576 image, just rendering after a pre-calc, which I feel is too high...

the animation looks cleaner and sharper, but I need to get the times down a bit more if possible!

Cheers, Mike

[zeronove]

Hi Mike,
I'm not an animation expert, I always do only still images so my tips could be not working fine for you
Said that, I would try to up the clr threshold and boost the material subdivs that's creating issue.
What about LC for glossy, is it on or off? and its local settings?
Subpixel and clamp settings in color mapping?

[fewlo]

Hi Mike,
I'm not an animation expert, I always do only still images so my tips could be not working fine for you

I do stills as well so all advice is greatly appreciated

What about LC for glossy, is it on or off? and its local settings?
Subpixel and clamp settings in color mapping?

lc settings attached, subpixel and clamp both checked

I would try to up the clr threshold and boost the material subdivs that's creating issue

I never normally move away from the default 0.01 for clr thresh, I've started using 0.005 now which has given me higher render times but better renders... as for the materials, generally is 24 a bit low for a 0.85 glossy material?

the two main problems I always suffer with in animations is 'dancing' white dots and noise in some of my glossies, removing filtering has obviously enhanced this issue, which is why I'd love to sort it out with my sampling. But can the samplerate element help with this?

thanks for the help so far, is there anyone else out there who has any advice, especially for animations?

Mike

[zeronove]

lc settings attached,

ehm.. where?

I mean that clr threshold could be not always better with lower values, in particular if you already had solved the glossiness otherways

[fewlo]

ooops, sorry, attached now!

re clr threshold, I understand now, I'll try back to 0.01 and just up the specific material....

cheers, Mike