Odd 3.6 nightly behaviour ?

[anthonyh]

I`ve playing with the latest 3.6 nightlies and I thought it must be my lack of Vray knowledge. (I mean it probably is anyway as I never fully understood real camera settings etc.)
So I`ve been testing the `restaurant` scene from the Chaos courseware to see if it`s just my scenes but I`m getting the same very odd results.
I have reset Vray and Scene Converted to make sure.
BF/LC Full Evaluation will render noisy on some objects where Adaptive is smoother (albeit with fireflies) with Progressive, Bucket is normally better but in dark areas it remains very noisy unless you drop the noise threshold to close to 0.001 or even lower. The 0.0 default is terrible.
BF/BF is really bad on certain objects in Progressive, it`s like sampling just stops for certain objects while others get refined as normal yet when you switch to Bucket mode it renders closer to what you`d expect (although noisy), both using the same noise threshold.
So I`m assuming either Vray has changed so much that even your own scenes aren`t up to date or I don`t understand how Vray 3.6 now works(entirely possible). I read in the forums that the default AA 1/24 Noise 0.01 values should be a good base but they don`t seem to be working here.
Strangely if I test my crappy 3.4 scene without resetting Vray it tends to render much better, much less noise in dark areas and less need to tweak.
attached a few images
thanks

[anthonyh]

Right, google is my only friend in this thread it seems...

So... https://forums.chaosgroup.com/forum/...n-older-scenes
from Yavor`s post

renderers.current.twoLevel_adaptiveMethod=1

so this seems to be the answer I need. It not only solves the denoiser issue which I was failing to get to work in these janky scenes but also solves the hideously noisy sampling issues above as well.
The big question though is why this script isn`t applied when the renderer is reset to scanline and back or when using Vray Scene Converter ?
I really shouldn`t have to copy/paste this script into 20,000(probably more) legacy scenes.
It`s completely scene breaking not to have it by default in 3.6... or at least as some kind of option somewhere obvious when loading older scenes etc ? Is that something that can be worked into 3.60.05 ?
thanks
anthonyh

[yavor.rubenov]

Hello,

Sorry for the missing initial reply and glad that you found the problem.
When opening scenes created before V-Ray 3.3 there should be a question about applying the new sampler - if you answer Yes, we set the new sampler type.
Scenes created in V-Ray 3.3 and later have it as default.
Also - when resetting to scanline and back to V-Ray the sampler should be reset to the new value. If you are seeing something different - can you share a scene where this happens?

Best regards,
Yavor

[anthonyh]

Hi Yavor,

thanks for replying.
The scene above is from Chaos course-ware and seems to be for 3dsmax 2018, not sure which Vray version. Our scenes are normally Vray 3.4. I do see the warning when loading old files but I often choose `no` to make sure it renders the same. However this issue only really started after loading the course-ware scene and choosing `no` then subsequently resetting Vray (scanline and back) and that was when the issue started. Subsequent resetting Vray doesn`t correct the problem, I assume because I already reset it.

I was testing `The Restaurant` course-ware and it`s default settings seem way off Chaos recommended defaults eg. MSR of 2, but it renders ok. So I reset Vray to see if it performs better with defaults and then it went wonky. It`s also important to note this only seems to happen with certain setting combinations and I think it`s just using Progressive render although I`d need to check Bucket further.
It`s most pronounced with BF/BF but also seems to be an issue with BF/LC but less pronounced. The only way to describe it is it`s like the Progressive sampling `freezes` on some objects while others continue to be refined further. It`s most obvious when comparing the Table Light feature with the Table itself.

Adaptive/Probabilistic/Full light Eval all seem have this issue with BF/BF.
Adaptive does`nt seem to have this issue when using BF/LC.

I`ve attached 2 scenes of the Restaurant, the default scene unaltered which renders fine and the scene after I reset Vray, both set to BF/BF.
Maybe it`s a setting I`ve changed and saved over default preset ? Don`t know if that that would explain it not working after resetting Vray though ?

thanks
anthonyh

[yavor.rubenov]

Indeed seems like you have some preset with different options.

I opened the default scene, reset V-Ray and rendered - it looks correct. Saved the image to history. Then I opened the your after reset scene, rendered and indeed it looks way off.

Here is a comparison of the render settings ("Compare V-Ray settings" option from the VFB history panel):


Saved value column contains values from the scene I reset to default (I don't have any presets). The current value column contains the values from the Render_Elements_Final - After Reset.max scene. There are multiple different values but the adaptive method is the most important one here.

[anthonyh]

Hi Yavor,

thanks for testing this. I have tweaked a couple of settings to my liking but I doubt I`ve changed `Two level Adaptive Method` as I`d never even heard of it until I googled it ! So what`s the easiest fix ? Uninstall and delete the presets ? If so which file do I need to delete so Vray is set back to normal operation (preset file) ?

thanks for the speedy reply.
anthonyh

[yavor.rubenov]

I guess you can just create a new empty scene with your defaults, change the two level method with the above MAXScript and then save the preset over the old one.

[anthonyh]

Hi Yavor,

Woops, I didn`t think of that ! No idea how it got messed up like that. Great stuff.

thanks
anthony

[yavor.rubenov]

You are welcome
Maybe originally when you created the preset you saved from some older scene with the old method..

[anthonyh]

You are welcome
Maybe originally when you created the preset you saved from some older scene with the old method..

Seems like the most likely idea. I`ll hopefully know better next time ! I`ll work through the list above and change it back.
thanks again for your help.

anthonyh