Video tutorials about using AOVs in MAXtoA can be found here.



Arbitrary Output Variables (AOVs) Manager and AOV Light Group Manager (via AOVs tab)

  • MAXtoA supports Cryptomatte AOV shaders.
  • An introduction to AOVs for compositing tutorial can be found here.
  • Multichannel EXRs are possible using All In One File (RGBA).
  • Tutorials using AOVs can be found here.
  • AOVs do not have any Exposure Control (tone mapping) applied to them. However, the beauty pass specified in the Common tab will, and this appears in the Rendered Frame Window. Unlike Render Elements, AOVs are saved by Arnold and do not show up in the window after rendering.

3ds Max does not support more recent EXR formats natively, and you may have issues using Arnold generated EXRs in your scenes. EXRs with only one layer should work.

AOVs are similar in concept to Render Elements, in that they separate out components of the rendered image as it is produced, and sends it either to a separate output file and/or as a channel in an EXR. Arnold supports output types and features not found in Render Elements.


Arbitrary Output Variables window


The Arbitrary Output Variables (AOV) window is available in the AOV tab in the Render Setup window. Here you can choose to Add AOVs using the AOV Wizard or manually using the AOV List. AOV light groups can also be managed using the AOV Light Group Manager window.


The main view shows an AOV list to add Drivers and AOVs (drag & drop). Roll over image to view AOV List.

AOV Wizard

The main view shows a wizard where you can Add Drivers and AOVs (also available in the + Add AOV File menu). 

Components

All In One File (RGBA)

Creates a default RGBA (beauty) AOV. Disabling this (on by default) enables you to add individual component AOVS.

Direct/Indirect

Here you can choose to split direct and indirect AOVs.


Split direct/indirect AOVs (All in One File: disabled). Combined enabled. Roll over image to view Combined: disabled.

Add New AOV Output File

MAXtoA takes a file-centric approach. You start defining your AOVs by first specifying the file type (+ADD AOV File) that you want to produce and then the AOVs you want to save to that tile type.

AOV List

+ ADD AOV File

Drag & drop AOVS from the AOV list into the main area where you can adjust the type, driver, and filter of the chosen AOVs.

File/AOV Name

The filename of the AOV.  The name of the output files can be renamed here. Multiple AOVs can be dragged onto a single AOVs group. This can be useful for light groups where you might want a diffuse AOV in both a red and blue light group.

Type

Here you can choose the file type (driver) format which you want to output from MAXtoA.

Data

Filter

The AOVs use the image pixel filter defined in the Arnold Renderer tab. Gaussian is the default.

Light Group

Choose between:

Same as File: (only available for AOVS) - The AOV will use the AOV Light Group setting defined at the file level. Same As File, All lights or default.

All lights: The AOV(s) will be rendered using all lights, regardless of AOV light group assignation.

Default: The AOV(s) will be rendered using the scene lights that are not assigned to a light group (or are assigned to the "default" light group).

Remove All AOV Files

Choose to remove all AOV files from the main pane.

Manage Light Groups

Opens the light group manager window.

Presets

Choose to load/save different AOV presets.

Custom AOVs

You can define custom AOVs in the scene via the Add Custom AOV button if you want to render a custom effect that is not available from the existing AOV list. This custom AOV can be used with any compositing software such as Nuke. You can write the output of a shader in a custom AOV via an aov_write shader. 


Output Path Tokens

Tokens (select a token), Select Output Folder and Open Output Folder


Tokens are used to generate dynamic AOV output paths. You can use tokens to define both the folder structure and the output filenames. If the generated path does not end with a valid filename extension (EXR, png.), the default name and extension of the AOV file will be added automatically.


If the output expression does not end by a valid file extension, the expression is assumed to be a path. The current valid end of expressions (extensions) are (case insensitive):
.exr, .deepexr, .jpg, .jpeg, .tiff, .png and .<AOVsFileType>


If the expression resolves as a path, "/<AOVsFileName>.<AOVsFileType>" is added for a single frame, "/<AOVsFileName><Frame>.<AOVsFileType>" is added for a frame sequence.

Tokens are case insensitive. 

<Frame> uses zero padding, 4 digits.


Examples:
1. Output paths


2. Output files


Opacity Example

The example below shows a plane with a checker texture connected to standard_surface.opacity. Currently, we do not support opacity composition in AOVs of RGB types. 

Indirect Diffuse AOV