Video Flickering

[AVAV]

Hey Guys!

This is my first interior rendering with Corona and I have two issues I can't seem to resolve:

1) the shimmering light under the table.

2) The actual noise flickering through the rest of the image. - I haven't had this issue with exterior renders, and have no idea what is causing this issue.

I am running the render with 30 passes and high quality corona denouncing.

Please see attached video file.

Any advise would be greatly appreciated! :)

Thanks!

Glen

[maru]

My bet is two things:
1) UHD Cache - what settings are you using? See: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515648
2) Denoiser. The base image quality may not be good enough after only 30 passes. You could try either disabling the denoiser or letting it render a bit longer (50 passes or more) and see if it's better.

Also, did you touch any render settings, or are you using the defaults?

[GeorgeK]

Greetings, these two screenshots will help you overcome some of the flickering and any fireflies that might appear on your footage. My suggestion is as previously mentioned by maru, to increase the passes of each frame or preferably work with Noise Level Limit of 4.0-5.0 and the rest be left on denoiser.

[AVAV]

Hi Guys,

Thanks for the feedback!

I have tried both of these suggestions and while it has reduced a great deal of the flickering, there is still noticeable flickering (see attached video).

It has also increased the render time to 60 hours for 120 frames @ 720P resolution. The CPU is 38.4Ghz Xeon. Does 60 hours seem excessive?

The settings are:

UHD Cache Animation (flicker free)
Load from UHD File
4.0% Noise Level Limit
Image filter Highlight claming 1.75 (use high quality filtering.

Thanks again for any thoughts!

[sprayer]

Looks like you uncheck this box
https://i.imgur.com/bnCZTrs.png


and you have missing floor on the left behind the door with vase

[AVAV]

Looks like you uncheck this box
https://i.imgur.com/bnCZTrs.png


and you have missing floor on the left behind the door with vase

Sorry, i don't understand. This box is checked.

Should I uncheck it?

Aslo, good pick up on the missing floor. Thank you!

[sprayer]

No it should be checked, strange on video it's looks like your noise pattern is flickering what this box should fix it

[GeorgeK]

Hi Guys,

Thanks for the feedback!

I have tried both of these suggestions and while it has reduced a great deal of the flickering, there is still noticeable flickering (see attached video).

It has also increased the render time to 60 hours for 120 frames @ 720P resolution. The CPU is 38.4Ghz Xeon. Does 60 hours seem excessive?

The settings are:

UHD Cache Animation (flicker free)
Load from UHD File
4.0% Noise Level Limit
Image filter Highlight claming 1.75 (use high quality filtering.

Thanks again for any thoughts!

Great, looks much better.

From what I see your noise is focused mostly on the glossiness of your floor and on the brick wall, I would like to know if you are using light-mix, frankly you shouldn't have this noise at 4%, personally I use 3.5% to 3.8% for animations. What's the value of your de-noising? Have you tried the scene with Corona 5 - 2.5D Displacement? I think it will improve your speeds.

Please provide the actual model of your Xeon in order to assess further.

[AVAV]

Hi Guys,

Thanks for the feedback!

I have tried both of these suggestions and while it has reduced a great deal of the flickering, there is still noticeable flickering (see attached video).

It has also increased the render time to 60 hours for 120 frames @ 720P resolution. The CPU is 38.4Ghz Xeon. Does 60 hours seem excessive?

The settings are:

UHD Cache Animation (flicker free)
Load from UHD File
4.0% Noise Level Limit
Image filter Highlight claming 1.75 (use high quality filtering.

Thanks again for any thoughts!

Great, looks much better.

From what I see your noise is focused mostly on the glossiness of your floor and on the brick wall, I would like to know if you are using light-mix, frankly you shouldn't have this noise at 4%, personally I use 3.5% to 3.8% for animations. What's the value of your de-noising? Have you tried the scene with Corona 5 - 2.5D Displacement? I think it will improve your speeds.

Please provide the actual model of your Xeon in order to assess further.

Denoising is Corona High Quality, amount 0.8, radius 1.0

CPU is Xeon CPU E5-2650 0 x 2

I am using Light mix.

And would be hesitant to go finer on the noise % as it is already taking incredibly long as it is.

I am not using Corona 5 2.5D Displacement. It will save some time I think but it is having to run 98(?) passes to reach 4% noise, so not sure if the 2.5 Displacement will help all that much in the scheme of things.

Thank you for your thoughts!

[rowmanns]

Hi,

In some cases the new 2.5d displacement has some rather large improvements.

It might be worth trying, as if it hypothetically saves 10% per frame it can add up to saving a large amount of time over the course of rendering an animation.

Cheers,

Rowan

[GeorgeK]

Hey again! Corona 5 will greatly improve your render time since many things have been optimized and the new displacement is much faster than the old.

Some things to consider:

- Your light-mix setup how many grouped lights it contains?

- How many values in your light-mix are above 3.0?

- Personally I would try to avoid using light-mix for animation, if the outcome though is preferred and unavoidable without light-mix, then lower noise limitation
on render settings would be advised (3.0% or 2.8% below this your render-times would become impossible with your current hardware).

- For post processing your footage, if you are using after effects, there are tools that can help with minor flickering and noise.

My personal notes on this. Your render times seem to be totally normal for the CPU's you are using, generally animations are time consuming, even on recent AMD thread-ripper CPU's most animations I've done go for 15-35min./frame per node. At worst 1hour per frame but rendering with multiple nodes. Still we would render for weeks.