Corona 1.6 Hotfix 2 and Noise

[hika]

Since upgrading to hotfix 2, we have been seeing excess noise in all of our scene files that rendered just fine previously on 1.6 hotfix 1.

Some of our DR slaves also have to constantly be restarted for almost every send. Sometimes 1 or 2 have to be restarted, other times all slaves have to be restarted

Perhaps this is a bug of some sort? Any input who be greatly appreciated. Thanks!

[Luis.Goncalves]

Me and my colleagues are starting to have the same impression.
We are not sure but in some scenes we get the impression that they got noisier.
This noise also seams to come from Hdri lighting (we do mainly interior shots lit with and Hdri and corona lights).

In some scenes even if we go down to 2 or 3% noise levels it's still quite noisy.

(Will update if we figure something out)

   

[Ryuu]

Does it take the same amount of time to reach the same noise level?

There's a new sampler used in 1.6.2 which produces a different noise pattern. The noise level calculation however does not take that into account and gives different numbers for the same level of noise (visually).

[hika]

Render times are actually longer with noticeable noise, and denoise amount set to 1.0 has almost no effect.

We did encounter a thread located here - https://forum.corona-renderer.com/index.php/topic,16959.0.html - in which maru suggests changing random sampler to stratified in development/debug mode.  Doing that helped out a lot with cleaning up noise and cutting render times.

We're still having issues with DR slaves randomly disconnecting or stalling though

[Luis.Goncalves]

We've been doing some tests and using the old sampler solves our noise problem.
From reading other posts we think that the problem comes from using DR. We'll leave an image rendering tonight with the new sampler but rendering locally and from what I've seen in another post the image will come out with less noise 

Booth images were rendered with DR. Noise level 5% and even if we left the new sampler rendering for 2 more minutes the image wouldn't get to the same visible noise level.

[Ryuu]

Thanks for the info. We'll investigate how the new sampler interacts with DR.

[Luis.Goncalves]

Small update
This is the same image rendered with the new improved sampler but on a single machine
As you can see the visible noise is way lower if compared to the image rendered with DR.

[Jpjapers]

Im also having issues with having to restart DR nodes

[maru]

There were a few reports about DR misbehaving after releasing 1.6 hf2, and the need to restart the nodes. But as it usually is with DR, most users do not experience any problems whatsoever.
Our dev team is looking into this, and I think we have enough data, but if you would like to report your issue, please gather the DR logs (https://coronarenderer.freshdesk.com/support/solutions/articles/12000002065), and contact us with a detailed description of the issue at support@corona-renderer.com .

[Dan Rodgers]

We have been having the DR issue since 1.6  - having to restart the CoronaDR on the nodes for them to pick up.

Also, now since 1.6.2 we are experiencing some odd noise in scene with a lot of bounced light.  Generally we render to around 2-3% noise and then run denoiser on around 0.4.  Since upgrading to 1.6.2 the noise in the scene is worse (much uglier in my opinion too), especially with DOF enabled we are getting some really nasty noise even with a 2% threshold, which would have given us near perfect results in the past.  The denoiser makes very little difference, and seems to bring out some parts of the noise a little worse too.

I have attached a crop of what I am talking about, this was rendered to a threshold of 2% noise, and rendered around 600 passes at 5k.. The results are AWFUL.  This scene was originally set up with 1.6.1 and rendered completely fine.... (also attached)

I don't really want to mess around with debug/dev settings to get this working, its not really feasible to do this across the studio, and is kind against why we moved to Corona...

Hopefully this get sorted soon...



Would there be any compatibility issues if we rolled back to 1.6.1?

[Ryuu]

We have just discovered a serious bug when using the DMC sampler in 1.6.2 in DR. We'll be releasing 1.6.3 soon, where this bug will be fixed.

In the meantime you can work around this issue by selecting another sampler in the debug settings.

Regarding using the scenes in older versions, I'm not sure to be honest. If it works, you will almost certainly have to select the appropriate sampler by hand as well.

[Dan Rodgers]

We have just discovered a serious bug when using the DMC sampler in 1.6.2 in DR. We'll be releasing 1.6.3 soon, where this bug will be fixed.

In the meantime you can work around this issue by selecting another sampler in the debug settings.

Regarding using the scenes in older versions, I'm not sure to be honest. If it works, you will almost certainly have to select the appropriate sampler by hand as well.

Thanks for the heads up

[Ondra]

fixed, builds coming out today

[maru]

Fixed in 1.6 hotfix 3: https://corona-renderer.com/download/
Please install it and test thoroughly.

[Luis.Goncalves]

Thanks for the update