DMC sampler

[BBB3]

Working great with IM. Clean and fast. Seems to kill render times with BF though, even when adjusting the subdivs accordingly. Any idea what might be causing this?

[pixela]

It's a difficult one indeed.


This is where your render elements come into play. If you turn on your lighting, reflection, specular, refraction and shadow passes, you'll be able to see each component as they are in the final image and be able to nail down where the noise is coming from. the samplerate element can also be useful to show you where is getting high aa samples (red) and where's getting low amounts (blue) and from that you can deduce that lower aa areas probably get more material samples.

Thanks for this great tip =)

[PDI]

Hey BBB3,

Not sure if u'r asking me or Dmitry Vinnik the question.

[BBB3]

Sorry, that was meant for you.

[PDI]

I will have to try some tests with brute force method.

Almost finished with test renders of car. Will post as soon as it's finished.

[PDI]

Car Tests




Here is the rendered image of a car I did using the method described above.
I have also included a relection, Indirection Illumination and SampleRate element.

It took about 1hour 38mins @ 4000px. The settings are pretting high and I didn't adjust any material subdivs. I think with some tweaking I could bring this time down.
I rendered this using 2 I7's with a average of 2.9ghz each.

As you will notice the head light did not finish rendering. I had to stop the render as it got stuck on this area. I think it's has something to do with displacement and material subdivs. I will try to sort it out and post images again.
No changes where made to the image, it is raw.

I think the SampleRate pass is a good example of what is happening. It seems that the AA is only happening on edges and the DMC Sampler is being left to collect samples thereby smoothing out the reflection, light etc. without too much help from the AA.

[zeronove]

You could do this manually but I started to find this strange and annoying. So I decided to just globally multiply all subdivs by 50.

may I ask you why do you type-in 50 instead of 20 (50 aa max x 8 material subdivs )as global subdivs multiplier?

nevermind ..maybe I've solved

[PDI]

I put 50 instead of 20, as 50 will counter act the AA Max Value of 50.
If you have a AA Max value of 50 and you multiply all subdivs by 50 then the correct subdivs sampling will be take, because the Subdiv's will be divided by the AA MAx Value before sampling.

[dsolod]

PDI,
I found your method quite interesting and I played with your rendering settings and I agree that rendering is fast with a decent quality.
However, for my interior scenes I observe a lot of noise in VRayRawLighting element which affects the whole image even with Clr thresh lower than 0.005. I played with lights separately but it did not help. I can get more clear picture if I increase the ratio "Global subdivs multiplier"/"Max subdivs" (for example 100/50) but the rendering time is increased almost linearly.
Could you share your experience with that issue please? How can I get cleaner diffuse direct illumination using your method without spending more time?

Thank you!

dsolod