Reflection question

[Builtdown]

Hi,

I would need some tips.
I have made an interior that has lots of lights and some reflective surfaces. Problem is that whatever I do I don´t seem to get nice clean reflections. Light reflections are all pixelated and bad looking. (See attachments.)
I used the wine glass spot as an example.

I think I have good render attributes but maybe there is something that I dont know about:

1. Wine glass is well Subdivided (200.000 polys)
2. Hot Pixel visibility 20%
3. Path Tracing
4. Max Samples 8500
5. Diffuse and Glossy depth 26
6. Caustic blur 90%
7. GI clamp 10

What should I look next?



Thanks!

[elsksa]

Hi,

These are unresolved sample areas, Adaptive Sampling seems to be missing from the listed settings and I assume, is disabled. Enabling it will tremendously help.

Another parameter is the ray depth, despite being scene dependant I would assume it's too high.

I strongly recommend to thoroughly consult this Octane Sampling Guide which pretty much answers almost all sampling questions.

I will reply on your other forum post but be aware that it isn't necessary to post twice as we end up seeing twice the same posts under "new posts".

[Builtdown]

Hi Elsksa,

I went through the link you sent and did a lot of testing. None of the tips made a lot of difference.
Adding a lot of samples helped. With ~25.000 samples the result started to be pretty good. (I know that so many samples is not a good thing.)

But I think the DOF is the big reason of those "unresolved spots". Without DOF it looks good almost right away.
Problem is that I want the DOF "look".

Is there any tips about DOF quality regarding to my case with those unresolved areas?


Thanks,

[elsksa]

I must insist, has Adaptive Sampling been setup (and properly accordingly to the scene)?
That's one of the best suited cases for it. It will help to sample areas that require it the most, here the DoF.

There isn't much to do besides what's written on the aforementioned page. Pretty much everything is in there. Therefore, I'm thinking you might have overlooked something somewhere.

Are you using a bokeh map (texture file)?
This could slow down rendering.

Could you post a screen grab of the Kernel settings?
To allow us to double check with you.

It is possible that a change of the kernel would help with heavy transmission.

[Builtdown]

I still think I did everything right and no bokeh map.
But good that you mentioned changing kernel. Because that was what really worked!

PMC kernel did exactly what I was looking after. I have never used PMC with interior pics but now it seemed to be the answer.
I attached some examples with bad PathTracing result and PMC result with approx. same time rendering.

[elsksa]

That's great looking, indeed. Glad it helped.
The practicality of Kernel choices in Octane. PMC also helps with volumetric scenes and Photon Tracing principally with caustics.
Comes handy when needed.

[elsksa]

I forgot to mention denoising. Have you considered it?
With Path Tracer coupled with Adaptive Sampling, the denoiser should be clean enough at 2K or 4K samples on average.

[Builtdown]

Thanks for the tip.
I wasn´t using Denoiser. Now with it it definetly made it look better.


PMC still more realistic but takes much more time compared to PT+Denoiser.