The following is a snippet from the upcoming documentation release. This snippet is not exhaustive, but it does provide enough of an overview to get started with the new AOV system. Please note this information is copyrighted, trademark protected, etc. by Otoy.
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Arbitrary Output Variables (AOVs) are artist-specified render and data passes generated by OctaneRender® that can be used for compositing, checking shader output, debugging issues, etc. AOVs can output a variety of different image output passes, as well as include data passes such as normals, object positions, material IDs, motion vectors and more. AOV nodes can create simple composites inside of Octane, which can be seen in the Live Viewer and output at render time, as well as output as freestanding files to be used in external compositing applications. These composites are managed with
AOV Groups and
Presets, available from
Render Settings > Octane Renderer > AOV Groups and
Render AOV Group tab. Supporting the AOV nodes are additional special material nodes, available in the Node Editor and Custom AOV options have been added to materials and to the Octane Object tag, to extend the functionality of the AOV system.
Octane Renderer Node
The Octane Renderer node houses the contents of the Octane Renderer Render Settings panel, inclusive of the Main tab, Overwrite Kernel Settings tab, AOV Groups tab and the Render AOV Group tab. For AOV work, the AOV Groups tab and the Render AOV Group tab contain the necessary control settings, and along with the AOV Node Editor. The Octane Renderer node allows for two input connections: Render AOV and Composite AOV, discussed below. Multiple inputs of these two types are supported. There can be only one Octane Renderer node per scene.
Render AOVs
Render AOVs (which include Auxiliary, Beauty, Custom, Denoised, Info, Light and Render Layer AOVs) are isolated RGB, RGBA and data components that can be used in Composite AOVs (via the Composite Output Layer node connected to the Render AOV Output nodes). Render AOVs are equivalent to the Render Passes of previous versions of Octane. Render AOVs are managed via the Render AOV group tab. Render AOVs are directly connected to the Render AOV input pins on the Octane Renderer node.
Composite AOVs
Composite AOVs are composites that are constructed with Render AOVs via the Render AOV Output nodes which are connected to Composite Output Layer nodes. Composite AOVs include the functionality of the AOV Output Group node, although this node is also available separately in the nodegraph (Octane Standalone requires this node to be connected between the Render Target node and the Composite AOV Output node. Composite AOVs are managed via the AOV Groups tab. This tab can be used to create AOV presets, and add additional Composite AOV pins to the Octane Renderer node.
AOV Node Editor
The Octane AOV Node Editor (seen in the illustration below) is used to build compositing networks that can then be rendered out in addition to standard Octane renders, either as separate files or as layers within some formats, such as EXR(Octane). The AOV node editor is the same node editor that Octane uses for materials; that said, it is best to keep the AOV nodegraph separate from any material nodegraphs in the scene for readability and maintenance purposes.
The AOV node editor is accessed via
Render Settings > Octane Renderer > Render AOV groups tab > Node Editor button (a new
AOV system button was added to the top of the Octane Node Editor workspace as of the 2021.1 release to allow for easy switching). A traditional Cinema 4D layered style representation of the AOV environment is also presented in the AOV Groups tab.
Global Texture AOVs
Global texture AOVs allow you to apply a texture to the whole scene including or excluding the environment. Global Texture AOVs are rendered as info AOVs, which means that the info AOV settings are applied to them as well. You can overwrite the alpha channel with your own texture, or use the default behavior which is equal to the alpha channel of the other info AOVs. Render AOV Output nodes can reference Global Texture AOVs in composites as needed.
AOV Composite Example
The images below are the result of three contributing Global Texture AOVs, used to build up the wireframe blend on the first image, and the depth fog on the second image.
The illustration below shows the node graph for the composite images above directly from Octane:
Each of the Global Texture AOVs have standard material nodes as inputs. These subgraphs are used to build up the effects that are then blended into the Render Pass AOVs connected into the Composite AOV Output Layer nodes and then into the Composite AOV Output nodes. These nodes are connected to the Composite AOV pins of the Octane Renderer node for final output.
