Denoise Next Limit Maxwell renders with Altus

Maxwell 4.1 and later with Altus

Maxwell 4.1 and later comes with Altus integrated. See for more information. Upgrade today!

You can watch a video tutorial about using Altus Denoiser in Maxwell 4.1. More technical details are available in the Denoiser section of Maxwell’s documentation. There’s also a great article 5 Tips on using the denoiser in Maxwell 4.


The remainder of this article is under construction and will be updated. If you find any issues with the documentation please contact us at


Altus Denoiser uses information from two rendered images to generate a high quality denoised image. This guide will explain how to setup and render the inputs to Altus. There are two concepts that Altus uses to generate denoised outputs:

AOVs (Arbitrary Output Variables) provide a way to render any arbitrary shaded component into different images. Typically renderers will only produce a final color for each pixel of the image (known as the beauty pass, or RGB pass), but you can break out renders into their component parts such as indirect lighting, diffuse color, reflections, shadows, mattes, etc. and save them as files individually or layers as part of a multichannel/multilayer EXR. See Recommended AOVs for more information.

Two images (called buffers) must be generated for each image. It’s important that each buffer is rendered with a different sample seed so that they will have unique noise patterns. The variance between the two buffers is what Altus uses to remove noise. Without variance, there is not enough information to remove noise. See Buffers for more information.

For information on how to run Altus once the correct inputs have been created see Usage.

Exporting AOVs

Recommended List of AOVs to use with Altus:

AOV type Altus Input Name: V-Ray Render Element Name
World Position pos Position
Bump Normals nrm Normals
Visiblity vis Shadows
Albedo alb Reflectance?
Caustics cau (Optional) Caustics

How to Output AOVs that are compatible with Altus (from 3ds Max)

First enable Maxwell as the current renderer in the to render settings. Then select Maxwell Render Tab. Under the tab expand the rollout General Settings. And in the Engine rollout select Production.


A Separate Maxwell render window will open automatically when you click the render button. You can stop the render from the top menu bar if needed.


Now go to Channels rollout. And select the necessary AOVs. Keep the extension as EXR.


Saving AOVs

Under the Channel panel there is ‘Output Mode’ dropdown with the options Separate or embedded. Selecting separate will output all the elements/AOVs. Selecting embedded will merge all the elements/AOVs in single channel/output.

The render panel will contain the output settings. You can define output directory here.


Exporting Two Buffers

On the left side of Maxwell Renderer there is a scene panel. In there is a CPU ID option. Use this to render images with different noise variance as required by Altus. Keep high difference in the values to produce best noise variance.