Author Topic: Interior rendering problem. Flickering and smudges  (Read 2424 times)

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Offline jayfade

Interior rendering problem. Flickering and smudges
« on: February 02, 2021, 03:46:48 am »
Hi,

Does anyboy know what det problem is with all the flickering and smudges on the white material?
I've set the max samples to 100 and 1920x1080p.
Really need to get it fixed... I've tried alla kind of differents settings.
Or should I go 400 samples? that will tkae ages to render out..
Not a valid vimeo URL

Offline KristofDeHulsters

Re: Interior rendering problem. Flickering and smudges
« Reply #1 on: February 04, 2021, 12:37:21 pm »
Hi there Jay,

The reason this flickering occurs is because of the low sample count. Keyshot is rendering each image in the sequence with 100 samples and then the denoiser is each time applied to that image. Because some of these images need more than 100 samples to properly resolve (this is depending on the angle you are shooting at and the complexity of the material and scene) the denoiser just blends whatever is there at 100 samples. What I would recommend is try to look for the image in the sequence that looks the worst, render that out to a sample count that you are happy with and use that sample count for the entire animation. You might also want to look in reducing the amount the denoiser affects your image if that is possible.

Hope it helps!

Offline designgestalt

Re: Interior rendering problem. Flickering and smudges
« Reply #2 on: February 05, 2021, 09:30:34 am »
My suggestion:
Do not! use the Keyshot Denoiser in an animation!
The Denoiser works image based, meaning, that it decides with every frame seperatly how to denoise it!
This will always cause flickering and also in a way, that it is much harder to remove the noise afterwards (i.e. After Effects)

The Denoiser in Keyshot does a good job for single images, but it does not really work very good for animations!
Though this is not a problem related to Keyshot only.
I can only really speak about Blender, but I have the same problems with Blender, although Blender provides three different Denoisers. None of them does a good job in animations!

What KristofDeHulsters said is definetly correct: 100 samples is not enough!
You might get away with a bit higher count and a decent Denoiser in After Effects. But I suggest to buy a Denoiser Plugin for AE. The free ones are mostly a waste of time in my eyes!
I use NEAT Video and this Plugin does a really good job!
If you don´t want to spend money, you have to crank up the samples and may have to play around with the lighting, but the blotchiness might by a hard task to solve...
Search for "Blotchy walls" or similiar in the forum, you will find a ton of related posts...

cheers
designgestalt

Offline jayfade

Re: Interior rendering problem. Flickering and smudges
« Reply #3 on: February 07, 2021, 10:00:40 pm »
Hi there Jay,

The reason this flickering occurs is because of the low sample count. Keyshot is rendering each image in the sequence with 100 samples and then the denoiser is each time applied to that image. Because some of these images need more than 100 samples to properly resolve (this is depending on the angle you are shooting at and the complexity of the material and scene) the denoiser just blends whatever is there at 100 samples. What I would recommend is try to look for the image in the sequence that looks the worst, render that out to a sample count that you are happy with and use that sample count for the entire animation. You might also want to look in reducing the amount the denoiser affects your image if that is possible.

Hope it helps!

Thanks for your reply! The render in the video doesn't have the denoiser on..
I've tired to render a new sequence with 300 samples now and in the worse scenes 300 samples looks clean now. But when I scroll thru the images I still see some flickering and smudges but not as much as before.. Its not even and complex material. It's a standard white paint material.
Maybe neat video will save the last bit?
Will post a full render as soon as the render is finished. So far 1600 frames and it took me 7 days on a AMD ryzen 5950x 300 samples at 1920x1080.

Offline jayfade

Re: Interior rendering problem. Flickering and smudges
« Reply #4 on: February 07, 2021, 10:07:03 pm »
My suggestion:
Do not! use the Keyshot Denoiser in an animation!
The Denoiser works image based, meaning, that it decides with every frame seperatly how to denoise it!
This will always cause flickering and also in a way, that it is much harder to remove the noise afterwards (i.e. After Effects)

The Denoiser in Keyshot does a good job for single images, but it does not really work very good for animations!
Though this is not a problem related to Keyshot only.
I can only really speak about Blender, but I have the same problems with Blender, although Blender provides three different Denoisers. None of them does a good job in animations!

What KristofDeHulsters said is definetly correct: 100 samples is not enough!
You might get away with a bit higher count and a decent Denoiser in After Effects. But I suggest to buy a Denoiser Plugin for AE. The free ones are mostly a waste of time in my eyes!
I use NEAT Video and this Plugin does a really good job!
If you don´t want to spend money, you have to crank up the samples and may have to play around with the lighting, but the blotchiness might by a hard task to solve...
Search for "Blotchy walls" or similiar in the forum, you will find a ton of related posts...

cheers
designgestalt

The problem is that I havn't use the denoiser in the render so thats why im so confused why this happens.
I tried to render a new animation now with 300 samples and in the worse scenes, 300 samples looks clean in the preview window but when scrubbing thru the images I can still se som blootchy and smudges..
I will try neat video. Thanks for the tip!
Something I've notice is that Keyshot have some really hard time to solve white material in some lighting conditions.
I've tried both product mode and interior mode.