Custom AOVs

Introduction
Creating Custom AOVs
Custom AOV Options

Default Shader

Store Color To AOV

Beauty Input
AOV Inputs
Store Color To AOV Examples

Store Scalar To AOV

Beauty Input
AOV Inputs
Store Scalar To AOV Example

Store Integer To AOV

Beauty Input
AOV Inputs

Introduction

When the Integrated AOVs aren't enough and you need to output more specific types of render data alongside your beauty renders as an AOV you can turn to Redshift's Custom AOV.

A Custom AOV lets you do things like override every object in the scene with a texture shader for quick custom matte AOVs, a custom ambient occlusion AOV, or pass through information on a per-material basis like specific texture mattes by making use of a Store Color/Scalar/Integer to AOV node.

Custom AOVs can not be used to render surface shaders like the Redshift Material, Incandescent, Car Paint, SSS etc.

Creating Custom AOVs

You can create Custom AOVs in the same way as any other AOV covered here.

Custom AOV Options

Houdini Custom AOV

Custom AOVs have most of the same options as any other AOV and you can read about these shared options here. The one key difference is the Default Shader option covered below.

Default Shader


Custom AO	Wireframe	Triplanar texture

A Custom AOV's default shader option can be used to quickly create a custom override of every object in the scene. Here you can plug in any texture or utility shader to output any kind of information you'd like. Above are some examples of the AOV example scene overridden with a custom ambient occlusion shader, a wireframe shader, and even a completely random wood texture map that is using a triplanar node to apply this to the entire scene.

Store Color To AOV

Houdini Store Color To AOV with an AO shader set to AOV Input 0 and two empty AOV Inputs

A Store Color To AOV is a pass-through node used to output color data to a Custom AOV for specific materials already applied to objects in a scene.

To control which material gets this connection you pass a material shader through the Store Color To AOV node's "Beauty Input." So instead of the material shader being connected directly to the surface port of the Redshift material, the Store Color To AOV is connected directly to the surface shading port as pictured below.

Houdini Store Color To AOV graph

Beauty Input

This is where you connect your Redshift material to pass through the Store Color To AOV node.

AOV Inputs

This section is where you connect your texture / utility shader or set the color to be output to the specified Custom AOV.

AOV Inputs are output in an additive fashion, because of this, you can actually set multiple AOV Inputs to the same Custom AOV and they will be added together.

AOV Input

Each AOV Input serves as another spot to output custom color data.

AOV Name / Custom Name

This section determines which Custom AOV is used as the output for the related AOV Input.

Store Color To AOV Examples


Custom Blend: Additive example	Custom Matte

The Custom Blend example demonstrates the additive nature of the Store Color To AOV node and how two AOV Inputs can be output to the same Custom AOV. The Custom Blend AOV has a black and green fresnel plugged into the Custom AOV's default shader slot, applying this green fresnel to every object in the scene. The drinking glass shader passes through a Store Color To AOV with two different AOV Inputs that output to the same Custom AOV as depicted below.

Houdini Custom Blend Store Color To AOV parameters with both AOV Inputs set to "Custom_Blend"

Houdini Custom Blend example graph

In the one AOV Input slot is a simple flat red color, this added with the green fresnel results in the orange color on the perpendicular edges of the drinking glass.
In the other AOV Input slot is a black and blue ambient occlusion shader, this added with the green fresnel results in the magenta color around the two lemons and the table near the glass.

The Custom Matte example is a simple one, making use of different flat colors for each material in the scene to create a custom multi-colored clown matte pass that can be used for keying and isolating different parts of the render.