How to denoise Arnold renders for optimal results in 3ds Max
Autodesk Support
Oct 8, 2023
Products and versions covered
Issue:
In some instances, Arnold renders in 3ds Max show varied amounts of noise within the final rendered image. This article provides guidance on how to remove noise from a scene file rendered with the Arnold (MAXtoA) plugin and produce the best results and settings while minimizing render times.
For example, an interior lighting scene may show noise in reflective objects or in dark areas of the render, but cannot be resolved by increasing the Camera AA samples only.
Environment:
Arnold (MAXtoA) plugin
Causes:
Noise within a render is most commonly due to lower Sample values in the Render Setup window or low Samples in light objects themselves.
Solution:
Use AOVs to filter noisy channels
AOVs (Arbitrary Output Variables) can be used to help differentiate which specific channels contain noise in the Arnold render, this way it can be removed without increasing the global Camera AA samples. Increasing global samples will also increase the overall render times of a scene.
To use AOVs for noise diagnostics:
In 3ds Max, go to the Rendering menu.
Choose Render Setup (F10).
Select the AOVs tab.
Use the steps shown by Technical Specialist, Jose Elizardo, on creating AOV outputs for specific channels to reduce the noise within a scene:
An OptiX Denoiser pass can also be added to the final beauty render, rather than increasing Samples values more than necessary. The tool can be used to remove smaller areas of noise (Specular channel, Diffuse, SSS, etc), as it will give quality results after processing the render.
Note: Be careful when using the OptiX Denoiser, as fine details can assume a more painterly effect when the automatic AI denoising is generated.
The Arnold Denoiser is a stand-alone program executable to post-process and denoise images. It works on EXR files with multiple layers (merged) and outputs an EXR file with the denoised layers. It takes into account multiple frames and multiple light AOVs. Like most denoisers, it considers a neighborhood around the current pixel and looks for similar neighborhoods inside a given search area to blend together. To use the Arnold Denoiser, images need to be rendered via the Arnold EXR driver.
To use the Arnold denoising options listed, see the following tutorial video:
