Versions Compared

Old Version 16

changes.mady.by.user Gergana Lilkova

Saved on

compared with

New Version 17

changes.mady.by.user Gergana Lilkova

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Overview

...

Section
Column
width48%60%

The V-Ray Denoiser takes an existing render and applies a denoising operation to it after the image is completely rendered out via normal means. The denoising operation detects areas where noise is present and smooths them out.

Images can also be denoised using the Standalone Denoise Tool included with the installation of V-Ray for Houdini.

UI Text Box
typetip
For animations, it is recommended to use the standalone denoiser tool. It performs frame blending and reduces flickering.

The V-Ray Denoiser operates on other render elements (like RGB_Color) rather than being part of the rendering process itself, therefore the denoising operation does not require re-rendering of the scene.

There are three denoising engines to choose from - the Default V-Ray denoiser, the NVIDIA AI denoiser (V-Ray's implementation of NVIDIA's AI-based denoising algorithm), and the Intel Open Image Denoise.

When rendering, the V-Ray Denoiser automatically adds a few render channels in the V-Ray Frame Buffer which are required to guide the denoising algorithm. The two denoising engines require different render elements. Some of them are standard render channels like the diffuse filter color, the reflection filter color, etc. A few special channels are also generated for the Default V-Ray Denoiser:

  • The effectsResult channel holds the result of the denoising operations and the lens effects that are executed over that image. The RGB Channel button in the VFB will toggle between the effectsResult and original RGB color channels.
  • The noiseLevel channel is the amount of noise for a pixel as estimated by the V-Ray image sampler.
  • The defocusAmount channel is non-black when depth of field and motion blur are enabled and contains the estimated pixel blurring in screen space.
  • The Denoiserchannel contains the result of the noise removal. This channel appears in the VFB only if mode is set to Show denoiser result channel.
UI Text Box
typenote

Currently the scene can contain only one Denoiser Render Element. Future versions of V-Ray will support multiple Denoiser Render Elements with different settings.

UI Text Box
typeinfo

VRayDenoiser can be applied to the Viewport IPR by enabling the Use Denoiser option from V-Ray Renderer > Export > IPR.

 

UI path: ||out Network|| > V-Ray Render Elements node > V-Ray > Render Channel > V-Ray Denoiser (RE)

 

Column
width2%
 
Column
width50%35%
before-after

Image Added

afterLabelDenoised
beforeLabelOriginal
Panel
borderStylenone

Image Removed

Panel
borderStylenone

Image Removed

 

Denoising Engines

...

VRayDenoiser offers a choice between the Default V-Ray denoiser, the NVIDIA AI denoiser, and the Intel Open Image Denoise. Each offers a different denoising algorithm that comes with different benefits. Each offers a different denoising algorithm that comes with different benefits. See the denoising engine examples below.

Default V-Ray Denoiser - V-Ray's denoising algorithm. It can utilize the CPU or the GPU (AMD or NVIDIA GPUs) to perform the denoising. It is consistent when denoising render elements, as it applies the same denoising operator to all render channels, which means that it is recommended for denoising the render elements to be used for compositing back the beauty image. In addition, it comes with a standalone version, which is recommended for denoising animation by using frame blending.

NVIDIA AI Denoiser - V V-Ray's integration of NVIDIA's  AIs AI-based denoising algorithm. The  The NVIDIA AI Denoiser requires an NVIDIA GPU to work, regardless of whether the actual rendering was performed on the CPU or GPU. This means that rendering on the CPU will still require requires an NVIDIA GPU for denoising with the NVIDIA AI Denoiser and has some advantages and drawbacks compared to the Default V-Ray Denoiser. For example, the NVIDIA AI the NVIDIA AI Denoiser performs the denoising faster, but is not consistent when denoising render elements. This means that there will be differences between the original RGB image and the one reconstructed from render elements that are denoised with the NVIDIA AI the NVIDIA AI Denoiser. It also doesn't support cross-frame denoising and will likely produce flickering when used in animation.

UI Text Box
typenote

The Nvidia AI Denoiser only works on Nvidia Maxwell and newer GPU architectures. 

...

Parameters

...

Section
Column
width50%60%

Enabled – Enables V-Ray Denoiser.

Name – The – The text added to the end of the rendered file, when saved as a separate file (e.g. myrender.Denoiser.vrimg).

Engine – Allows – Allows choosing between the Default V-Ray denoiser, the NVIDIA AI denoiser, or Intel Open Image Denoise. Note  Note that, the the NVIDIA AI Denoiser requires an NVIDIA GPU. See the the denoising engine examples below.

Hardware Acceleration – Uses the GPU device(s) to accelerate the denoising calculations. In case there is no compatible GPU device, denoising automatically falls back to use the CPU, even if the option is enabled. When the NVIDIA AI denoiser is used, this option is not available, as it requires an NVIDIA GPU.

Temporal Mode – Only available with the NVIDIA AI denoiser. When enabled, the Denoiser uses information from previous frames to create a smoother transition. Useful for rendering animation.

Preset – When using the Default V-Ray Denoiser, use the presets can be used to automatically set the Strength and Radius values.

Default – Applies a mid-level denoising.
Mild – Applies a more subtle level of denoising than the Default preset.
Strong – Applies a stronger level of denoising than the Default preset.
Custom – Allows the Strength and Radius parameters to be set to custom values.

Mode – Specifies how the results of the Denoiser are saved.

Only Generate Render Elements – All render elements required for denoising are generated so that denoising can be done with the Standalone Denoise Tool. The information calculated within them is not applied to other render elements, and no V-Ray Denoiser Render Element is generated.
Hide Denoiser Element – The VThe V-Ray Denoiser channel Denoiser channel is not present separately in the VFB. The effectsResult channel The effectsResult channel is generated with the denoised image.
Show Denoiser Element – The V-Ray Denoiser Render Element is generated to contain a denoised version of the RGB Color Render Element using the specified settings. The original render elements, including the RGB Color Render Element, are not changed.

Radius – Specifies the area around each pixel to be sampled for determining how to denoise a given pixel. Larger values produce smoother results, but slow down the denoiser.

Strength – Determines how strong the denoising operation is. Larger values remove noise more aggressively, but may blur the image too much.

NVIDIA AI Upscale –  When enabled, the rendered image is internally calculated with half the resolution set in the render setup (in each dimension), and the denoised image is upscaled to the full resolution using NVIDIA's AI upscaling technology. NVIDIA's AI upscaling technology represents an advanced method based on machine learning which provides better and more detailed results when compared to a standard image interpolation. For example, a 3840x2160 resolution renders the image internally in 1920x1080 and the AI upscaling denoiser produces the final 3840x2160 image from the lower resolution render.

UI Text Box
typenote

Render elements that don't have the Denoise option enabled are upscaled using simple interpolation.

UI Text Box
typenote

It is recommended to use NVidia AI upscale option with the latest recommended NVIDIA driver.

Temporal Mode – Only available with the NVIDIA AI denoiser. When enabled, the Denoiser uses information from previous frames to create a smoother transition. Useful for rendering animation.

Panorama – Specifies that the denoised image can be wrapped around the left/right border. The denoiser can then use this information to avoid generating artifacts over the seamed area.

Denoise Alpha – Enabled by default. When disabled, the Аlpha channel remains undenoised.

Deep Output – Specifies – Specifies whether to include this render element in deep images.

Column
width5%

 

Column
width45%35%

Image RemovedImage Added

 

Suggested Render Settings

...

Example: Default V-Ray Denoiser


The example below illustrates how the Default V-Ray Denoiser works after more samples are made with the Progressive image sampler. When the samples are too few, there is not enough information for the denoising to produce a smooth result. You can compare the results between an image with applied denoising and without.

Section
Column
width10%30%
 
Column
width80%40%
Image slider
minLabelstartIndex1maxLabel64
Panel
borderStylenone

Image RemovedImage Added

Sampling pass 1

Panel
borderStylenone

Image RemovedImage Added

  Sampling pass 264

Panel
borderStylenone

Image Removed

  Sampling pass 4

Panel
borderStylenone

Image Removed

Sampling pass 8

Panel
borderStylenone

Image Removed

  Sampling pass 16

Panel
borderStylenone

Image Removed

  Sampling pass 32

Image Added

No Denoising

Panel
borderStylenone

Image Removed

  Sampling pass 64

Column
width10%30%

 

Section
Column
width10%

 

Column
width80%
Before after
afterLabelDenoised
beforeLabelOriginal
Panel

Image Removed

Panel

Image Removed

The original vs. the denoised image after 64 passes.

Column
width10%

 

...

 

 

Example: NVIDIA AI Denoiser

 

The example below illustrates how the NVIDIA AI Denoiser works after more samples are made with the Progressive image sampler. When the samples are too few, there

...

's not enough information for the denoising to produce a smooth result. You can compare the results between a render with applied denoising and without.

Section
Column
width10%30%
 
Column
width80%40%
Image slider
minLabelstartIndex1maxLabel64
Column
width10%

 

Column
width80%
Before after
afterLabelDenoised
beforeLabelOriginal
Panel
borderStylenone

Image RemovedImage Added

Sampling pass 1

Panel
borderStylenone

Image RemovedImage Added

Sampling pass 2

Panel
borderStylenone

Image Removed

Sampling pass 4

Panel
borderStylenone

Image Removed

Sampling pass 8

Panel
borderStylenone

Image Removed

Sampling pass 16

Panel
borderStylenone

Image Removed

Sampling pass 32

Panel
borderStylenone

Image Removed

Sampling pass 64

Column
width10%

 

Section
Panel
borderStylenone
Image Removed

Image Added

Panel
borderStylenone

Image Removed

The original vs. the denoised image after 64 passes.

No Denoising

 
Column
width10%
30%

 

 

...

Example: Intel Open Image Denoise

 

The example below illustrates how the Intel Open Image Denoise works after more samples are made with the Progressive image sampler. When the samples are too few, there's not enough information for the denoising to produce a smooth result

...

. You can compare the results between a render with applied denoising and without.

Section
Column
width10%30%
 
Column
width80%40%
 64
Image slider
maxLabel
minLabelstartIndex1
Panel
panel
borderStyle
none

Image RemovedImage Added

Sampling pass 1

Image Removed

Sampling pass 2

Panel
borderStyle
Panel
none

Image AddedImage Removed

Sampling pass 4

Panel

Image Removed

Sampling pass 8

Panel

Image Removed

Sampling pass 16

Panel

Image Removed

Sampling pass 64

 

 

Column
width10%
Column
width10%

 

Column
width80%
Before after
afterLabelDenoised
beforeLabelOriginal

Section
Image Removedpanel
Panel
borderStyle
none

Image Removed

The original vs. the denoised image after 64 passes.

Image Added

No Denoising

Column
width10%30%

 

 

Denoising Animations

...

When denoising animations, it is recommended to use the Standalone Denoiser Tool. Unlike the denoiser integrated in the UI, the standalone tool can do frame blending for animations, which reduces flickering. The integrated denoiser only works on the rendered frame and does not take the next and previous frame(s) into account, like the standalone tool does.

...