Adaptive DMC

[sebastian_k]

Hi!
Could it be that the max-setting for the adaptive DMC image sampler is not working correctly?
It doesn't make a difference at all if max-subdivs is set to 4 or 100, regardless of the DMC sampler threshold.
I have the same amount of noise in the blurry reflections.
If the max-setting is infact broken and the sampler does not adapt to it, then that would also explain why the vray universal settings do not seem to work.
The tutorials on the web describe that the image sampler will take care of the noise and guide the brute-force subdivs, but no matter what i do with the max-subdivs of image-sampler, brute force always is noisy.
So, is that a bug in the script or in vray standalone (maya2010, 32bit, OSX)?
Cheers!

[sebastian_k]

Re: Adaptive DMC

I had a look in the scripts and in 2 of them there was a type, saying "treshhold" instead "threshold" (dmc_treshhold_use_dmc). At first I thought that must be it, because it would somehow fit to my problem, but after fixing that it didn't help either.
Well, maybe that typo is there on purpose, but if you wanna fix, it is in the properties_render.py and in SettingsImageSampler.py

Ah, btw, in the material properties the UI says "Frensnel reflections", instead of Fresnel
Cheers!

[bdancer]

Re: Adaptive DMC

sebastian_k, thanks for the report - nice found! Fixed! =)

[nizu]

Re: Adaptive DMC

EDIT : Andrey was too fast ..fixed before i could reply , anyway maybe post below is still useful :

EDIT 2 : i tried last commit , all fixed, typos and missing max samples . Lighting fast as usual , thanks!

Hi,
I see the typo is in the VB python UI, but in the vrscene text threshold is spelled correctly.

However i don't see max samples in vrscene export :
...
dmc_minSubdivs= 1;
dmc_threshold= 0.010000;
dmc_show_samples= 0;
...etc..

But no "dmc_maxSubdivs" ? then yes ,seems max samples are stuck to default 4.


But anyway, if it's not missing from vrscene , I remember reading something : Maybe it's working but DMC sampler doesn't use max value "unless it really needs to".
Min-max sampling is similar to the max samples of IrMap or adaptive subdiv .. but raising it doesn't mean necessarily slower - higher quality renders.

It's linked to noise treshold , higher glossy reflection samples or using DOF .. I think "use DMC threshold" means it's actually the noise threshold that controls whether vray will ever take more than 1 (or min samples value) depending on how complex is the shading and how much noise is there.
Infact , if you raise min samples to 64 the render will slow down a lot ..still it's likely maxSubdivs missing in vrscene , you should indeed see a change raising max to 100 anyway.