Inconsistent noise level-passes

[Flavius]

Hi there,

I cam across a very peculiar (at least for me) situation. I have sent a simulation (which has phoenix fd foam) to my"render farm" consisting of two computers. I've set a noise level of 9.5
Before going to sleep I waited to see a couple of frames. Render times were around 6 minutes and then suddenly jumped to 17-18 minutes, literally the next frame (there is little change in the frames). So my deadline goes out of the window for this friday:( but i have to know what I did wrong

Then I watched 2 frames while they were rendering and I noticed that after pass 6 the noise level didn't update until pass 9. Pass 6 7 8 showed the exact same noise level and then at pass 9 it dropped way under my noise level of 9.5.  Maybe I was better off using pass level limit? The thing is towards the end of the animation there is more geometry so I thought it will need more passes to keep the same quality.

The same huge jump in render times happened on my second machine.



any ideas?

Thanks!

[Frood]

Pass 6 7 8 showed the exact same noise target

You mean noise level here I presume, your target was 9.5 (very high imho even when using a denoiser). Noise level is updated every 5 passes by default. I never understood that default value because the overhead to compute the noise level is usual tiny after it has been improved by the Corona team. And you run into quality difference issues when rendering animation and you get additional 4 passes in the worst case even when noise is already down to the target level. You can tell the renderer to update the noise level at every pass in "Developement/Experimental Stuff" -> "Adaptivity recalc. (passes)". You may set it to 1 there. First you have to tick "Enable devel/debug mode" in Render setup -> System -> System Settings to gain access to that rollout.

There have been reports of increasing parsing/render times rendering a sequence, also memory leaks, I'm not up to date about the status here but you have to see what exactly takes additional time (e.g. parsing? passes? ram?) in those later frames anyway.


Good Luck

[Flavius]

Hi Frood,

Yes, I meant noise level. I'm a bit tired.

I didn't know noise level is updated every 5 passes. It makes sense now, thanks!

Parsing is decent, the thing is I am rendering yachts and every single thing on it is reflective. Add that to the reflective water and Corona has some hard trouble figuring out the scene. I did some tests with adaptivity on and off and the time needed to render is almost the same. Plus the reflective fireflies are driving me nuts.

Another huge issue I have is that if I push the denoiser above 0.5, the reflection of the water in the hull becomes more splotchy than the 2004 mental ray photon mapping renders. Also denoiser destroys any detail in the water itself altough there's hardly any visible noise in there.

I thought of rendering the ship separate but I run intro a plethoria of other problems.. So last resort was to simply give it more time. There's hardly and GI in the scene needed, after all it is a exterior scene but I still need 15 minutes per frame on a modern 16 core CPU to get a decent (NOT noise fre image). and at 1920x1080, a pretty obsolete resolution now. 4K is out of the question,

[Frood]

You need a quick solution it seems, I could get into details (starting with the question which denoiser you use and if you have tested another, same about MSI settings, the scene environment setup in general and so on). But without having the scene this will get a neverending thread. So if you would be able to send your scene to Corona support via private uploader, they would be able to help you to get some sleep again :)


Good Luck

[Flavius]

haha, thanks man. Yeah I talked to Maru about it but I always hoped I can do it myself.... but I can't so I will send them the scene eventually.

Thanks again.