Optional Biasing

[riggles]

Agree, but i wish there were a feature like "region-Painting" where you could after renderstop paint over some areas and the render engine just renders those painted/marked pixels - like region render just with an paintable mask and the continue-render option. that would be great cause you could focus the render onto the hard to render spots manually and focus the power to the spots where its needed. that would be a manual bias

That's a cool idea, importance mask. In theory, the PMC kernel is supposed to analyze the samples and determine which areas need more samples than others. But that probably takes longer calculate than a mask that says "just put more samples here." In MODOs preview render, you can hover your cursor over where you want more samples and it will give priority to that area while it's rendering. I got so used to using this feature that I find myself trying to do that in the Octane viewport and briefly wondering why nothing is changing.

[TBFX]

Agree, but i wish there were a feature like "region-Painting" where you could after renderstop paint over some areas and the render engine just renders those painted/marked pixels - like region render just with an paintable mask and the continue-render option. that would be great cause you could focus the render onto the hard to render spots manually and focus the power to the spots where its needed. that would be a manual bias

That's a cool idea, importance mask. In theory, the PMC kernel is supposed to analyze the samples and determine which areas need more samples than others. But that probably takes longer calculate than a mask that says "just put more samples here." In MODOs preview render, you can hover your cursor over where you want more samples and it will give priority to that area while it's rendering. I got so used to using this feature that I find myself trying to do that in the Octane viewport and briefly wondering why nothing is changing.

In v2.0 you can use the region render to help clean up noisy areas in a render, but obviously only within a rectangular selection.

T.

[MaTtY631990]

I know PMC is the slowest kernel but the parameters option maxrejects can be used to control the bias of the result and in return should cut the render time down. I have tried it myself , but to no avail.
Has anyone else had luck with this setting.

[dsyee]

Agree, but i wish there were a feature like "region-Painting" where you could after renderstop paint over some areas and the render engine just renders those painted/marked pixels - like region render just with an paintable mask and the continue-render option. that would be great cause you could focus the render onto the hard to render spots manually and focus the power to the spots where its needed.

I was thinking this exact same thing! Been using region render for that, but it's obviously a little tough when it has to be a rectangle.

that would be a manual bias

FYI, this isn't what "bias" (http://en.wikipedia.org/wiki/Bias_of_an_estimator) means.

[gueoct]

Agree, but i wish there were a feature like "region-Painting" where you could after renderstop paint over some areas and the render engine just renders those painted/marked pixels - like region render just with an paintable mask and the continue-render option. that would be great cause you could focus the render onto the hard to render spots manually and focus the power to the spots where its needed. that would be a manual bias

This would be great!
Check out the pictures gabrielefx posted here http://render.otoy.com/forum/viewtopic.php?f=27&t=40861
After ~ 50 minutes/12bounces/8000smp/1600x900px with 4 Titans there is still so much grain left;
that`s is truely sad!
So, some region-painting would help a lot with those kind of scenes.
i think iray wanted to introduce something like that; not sure if it ever came out...

[Stahlwolle]

hey guys,
after a few testings with the region-render tool i can tell that its doing pretty same thing as i wished with region-painting. okay, its no organic form but at least it does not restart the complete render so you can stop your render after most of the image is noisefree and focus the gpu on the hard-to render regions with the tool - thats a big step forward in my opinion cause you dont have to sample the clean regions any more - maybe an algorithm could do that job in further versions of octane? im no expert but maybe such an algorithm could check the noise (difference in brightness and colour) - chk if its the texture or if its render-grain and focus the render to the pixels where grain is spottet. i know octane is a very "young" programm and i think the teams doing fine with it - wonder more about the effectivity-loss of the cudas - sounds a bit like "sinking boat" if the 580 gtx is same speed as a titan...

[Stahlwolle]

pardon... 590

[riggles]

maybe an algorithm could do that job in further versions of octane? im no expert but maybe such an algorithm could check the noise (difference in brightness and colour) - chk if its the texture or if its render-grain and focus the render to the pixels where grain is spottet.

That's basiclly what the PMC kernel already does. It examines the sample values and focuses more samples in high-contrast areas while lowering sample priority in low contrast areas.

[Stahlwolle]

for sure? can someone from octane-renderteam can verify this? if this would be true, wheres the value to adjust the threshold?
i know the slider to adjust the focus on the primary and secondary bounces but i would wonder a lot if the pmc would differ beyond that - mean: it says sample per pixel and that says a lot - i think thats so bruteforce as bruteforce can be..

[riggles]

Here's link to a white paper on PMC (Population Monte Carlo) path tracing. It's an adaptive algorithm, not a simple threshold that you control with a slider.
http://pages.cs.wisc.edu/~yu-chi/resear ... pmc-pt.pdf