which denoiser?

[super gnu]

we now have 3 different denoisers .. which one is actually best for which scenario?

[seandunderdale]

Ive found Intel one is best for me. The other two either messed up alpha channels through glass, or things behind glass (driver inside a car).

[sirio76]

+1 for the Intel denoiser.
I hope it will get GPU acceleration soon.

[Muhammed_Hamed]

Hi super gnu

You can add multiple Denoiser elements, each in its separate channel. And compare in post
the V-Ray denoiser is very good with animations, I usually use that + AI denoiser I mix them in post depending on the results I have.
The V-Ray Denoiser runs on AMD and Nvidia GPUs, and Intel or AMD CPUs. It is very efficient on GPU memory usage
The AI denoiser is best for IPR rendering, specially the GPU IPR. The AI Denoiser deals with high frequency noise better than the other denoisers.
The Intel Denoiser is great as well, preserves details and doesn't produce smoothing, we are keeping an eye on the GPU version. We will test it whenever it is available

On another note, V-Ray 6 improves the Intel and AI Denoisers. They have better quality and could preserve shading details better
We implemented a new device manager in V-Ray 6, you will be able to select a specific device for your denoising, separate from Rendering. This works at the moment in the Beta

Best,
Muhammed

[Muhammed_Hamed]

The other two either messed up alpha channels through glass, or things behind glass (driver inside a car).

This is something we can improve, specific to V-Ray GPU. We will get to that soon I hope

Best,
Muhammed

[glorybound]

I just tried Intel on an exterior and I couldn't use the results. I have to re-render using V-Ray Denoiser.

[super gnu]

I was asking pretty much because i never use the denoiser, so have not kept up with developments. id much rather leave a render overnight and have it well sampled.. today i needed to get a render out really quick.

Every time i use the denoiser i find myself seeing artefacts in the under sampled areas that i find much more unpleasant than a bit of noise.. by the time those have gone completely, the image is usually pretty clean without denoising anyway. plus the perfect "smoothness" of the well sampled areas looks off to me too, it may "preserve details" but i always have the sensation its being "smooshed out"

[sirio76]

Default denoiser may produce artifacts when dealing with firefly, the Intel denoiser will remove it without artifacts.

[seandunderdale]

Default denoiser may produce artifacts when dealing with firefly, the Intel denoiser will remove it without artifacts.

I love that about it. So so awesome a cleaning up an image. I render every single render with intel denoise. Its the first thing I do when I make a new Maya file. I might sometimes save out the non denoised beauty and blend in post if I find something has smoothed out too much, like car paint flake. But I also find running IPR renders with denoise helps it looks a lot more real a lot sooner. I guess its down to personal taste, but I rather see a smudgy denoised render sharpen up and resolve, than a grainy image slowly reduce grain.

[Muhammed_Hamed]

Thanks for sharing everyone, it is very helpful
All of the denoising options are evolving, it might be a good idea to go back and test from time to time.

[Joelaff]

I find all the denoisers to be relatively useless for production VFX animation. They throw away too many details, and produce too many artifacts.

I keep trying them and keep being disappointed, even with the post stand alone denoising (which is the best).

Blending the denoised output with the noisy version helps, but still never seems to benefit things given all the extra steps vs just increasing the quality of the render to begin with.

[super gnu]

I find all the denoisers to be relatively useless for production VFX animation. They throw away too many details, and produce too many artifacts.

I keep trying them and keep being disappointed, even with the post stand alone denoising (which is the best).

Blending the denoised output with the noisy version helps, but still never seems to benefit things given all the extra steps vs just increasing the quality of the render to begin with.

this has been my experience too.. last night i left a render going.. a big lego model with tons of tiny geometric details and subtle textures (fingerprints, microscratches etc) i used the denoiser, and even now, after running for 6 hrs, and having a fairly acceptable image without denoising, the denoiser seems to kill the finer detail of the textures and, in the noisier areas, the logos on the brick studs.. turning off the denoiser, yeah, theres a bit of grain in shadowy areas, but everything looks sharper, and the logos are clearly visible and sharp amongst even the noisy areas... id much rather have the noise.

im sure there is a place for denoising, but i would not currently consider it as something to "leave on"

[Joelaff]

I just had a shot with bubbles in a liquid drink and the Intel denoiser actually worked very well. Not a lot of high-frequency detail in it (no textures per se, just refraction).

Any update on the GPU version of the Intel Denoiser? Is Chaos training it specifically for VRay? It seems they offer a toolkit to do that.

Intel® Open Image Denoise v2.2.2

• Now supports full cross-vendor denoising across all platforms including x86 and Arm* CPUs as well as Intel, NVIDIA*, AMD*, and Apple* GPUs. This includes ARM support on Windows*, Linux*, and macOS*.
• Integrated GPU support in Intel® Core™ Ultra processors (formerly code named Meteor Lake) for continuing iGPU support

Any chance of getting the multi-frame blending temporal denoising with the Intel denoiser? Not sure they support that, do they?

I wonder if there is a way to link to the Intel library so that users could update theirs from Intel without having to wait for Chaos to do it? (Like a shred library) I am guessing no?

[sirio76]

That would be very useful, I hope they include the new version soon

[Joelaff]

Does the temporal denoising do something special other than:

For each pixel
   Get its world position
   Get the pixels with the same world position (+/- some epsilon) from previous and next frame 
   Average those pixels
   If this average is within some threshold of the original pixels values use the average, otherwise do not change (or lerp)

Maybe do that before running the denoiser itself.

I’ve done similar before in the post, but never bothered incorporating the world positions. Seems reasonable.