Redshift AOV Guide: Using Passes Effectively in Architectural Renders

1. Decide which AOVs you need

An AOV is an output type that stores pixel information from a render in separate passes. Redshift’s built-in Integrated AOVs can separate components such as diffuse lighting, reflections, refractions, global illumination (GI), emission and subsurface scattering. This means you may be able to adjust reflections or the GI contribution in an interior render later without rendering the entire scene again.

Start by considering the post-production changes you expect to make. Use the Reflections AOV if you need to adjust reflection intensity; use the Specular Lighting AOV if you need to isolate light reflections. Redshift documentation specifically distinguishes the reflection pass, which contains environment reflections, from the specular pass, which contains reflections of lights. The Depth AOV provides depth data that can be used to create a depth-of-field effect in post-production. Rather than adding every available pass, select only the components you actually plan to edit to keep file and compositing management simple.

2. Create AOVs in Cinema 4D

1. Make sure Redshift is the active render engine in Cinema 4D. AOV settings are in the AOV tab of Redshift’s Render Settings window.

2. Open the AOV Manager. You can access it from the relevant button in Redshift render settings, the Redshift menu or the Render Settings icon group.

3. Drag the pass you want from the Available AOVs list on the left into the middle panel, or double-click it. In the middle panel, you can select, reorder or delete passes; the right panel displays the settings for the selected AOV.

4. Add a Custom AOV if you need scene-specific data. This is useful for outputs such as a custom ambient occlusion pass or specific data from materials. Custom AOVs can be set up with a default shader applied to all objects, or on a per-material basis using the Store Color, Store Scalar and Store Integer To AOV nodes. These nodes route the material shader through Beauty Input while sending custom data to the designated AOV.

Do not use Custom AOVs to render material shaders such as Redshift Standard Material; according to the documentation, they are not designed for this purpose. If multiple AOV Input nodes are connected to the same Custom AOV, their outputs are added together. Keep this behavior in mind when designing custom passes.

3. Choose an output method for your workflow

AOVs can be saved using Cinema 4D’s Multi-Pass system, Redshift’s own Direct Output system, or both. Enabling both means files are generated by each system separately, which can increase storage requirements. The best choice depends on your viewing, saving and team-sharing needs.

Multi-Pass offers benefits such as Picture Viewer integration and automatic management of AOV images in TeamRender. However, it uses a single file format for all AOVs and offers more limited control over naming and ordering. Direct Output provides separate saving options for each AOV, including dedicated output support for DeepEXR and third-party denoising. However, AOV files do not appear in Picture Viewer, and output paths must be set manually to suitable locations, such as network shares, for TeamRender.

4. Set up compositing and adapt it to architectural workflows

With standard shading AOVs, the relevant components are combined by adding them to the base composite. For more detailed control, a Raw AOV workflow separates material color from lighting contribution. For example, Diffuse Lighting Raw provides lighting data without multiplying it by the material’s diffuse color. In this workflow, multiply Diffuse Filter by Diffuse Lighting Raw, then add the result to the other components. Multiply GI Raw by Diffuse Filter and add it to the composite as well. Reflections Filter is similarly combined with the raw reflection data.

In scenes with volumetric fog, the order matters: first multiply the main composite by Volume Fog Tint, then add Volume Lighting and Volume Fog Emission. Changing this order can prevent you from correctly establishing the fog’s darkening effect on the scene. Before rendering again, check the passes in Redshift RenderView; according to the documentation, at least one of the Multi-Pass or Direct Output methods must be enabled to view AOVs there.

In architectural visualization, this approach is particularly useful for interiors and product scenes where separate revisions to materials, lighting and reflections are expected. Use Clay Mode in the interactive preview to examine light distribution independently of materials. Progressive mode provides fast feedback as the scene changes, but may involve compromises in detail and image cleanliness. Bucket mode produces a cleaner result, but restarts the calculation when the scene changes. Choose according to the balance you need between revision speed and preview quality.

Common mistakes

• Enabling Multi-Pass only for the AOV while leaving the Multi-Pass option in the general Render Settings turned off. Cinema 4D Multi-Pass output must be enabled in both places.

• Forgetting to account for the additional files and storage impact when enabling Multi-Pass and Direct Output together.

• Treating Reflections and Specular Lighting as the same data: one contains reflections, while the other contains reflections of lights.

• Adding Raw AOVs to the composite without multiplying them by their corresponding filter passes.

• Failing to set output paths when using Direct Output, particularly in TeamRender.

These steps are based on Maxon’s Redshift help documentation for Cinema 4D; the pages do not specify a particular software version number.