Cinema 4D R2026 Color Management

Summary

With Maxon Cinema 4D R2026 color management switched to a new default for new projects. It’s making use of the OpenColorIO frame work, both for Redshift and Standard/Physical renderer. Additionally it defaults to the wider color space of ACEScg and its tone mapping companion. This replicates the ever more common ACES workflow inside Maxon Cinema 4D.

This document outlines and guides through these changes.

Status Quo prior R2026

Prior R2026 project color management settings were set to “Legacy”. This replicated the color management behavior of Maxon Cinema 4D that had been used until then.

The behavior was as follows:

• Redshift - Redshift used its own color management via its render settings. These were already OpenColorIO based and used the ACES color spaces.
• Standard/Physical - both used the old “linear workflow”, essentially a ICC profile based color management known from Photoshop, the OS and similar applications.

R2026 color management

Overview

Here is a brief overview of how colors are managed in R2026.

Essentially colors from any scene components that contribute to rendering need to go through a series of colors space transforms, from an input color space to a render color space to the final display and monitor color space. This is necessary because texture or asset colors can come in different color spaces, rendering typically happens in a linear space and the rendering deliverable dictates the display space.

Input Color Space

This is the color space of any components that contribute to the rendering.

Typical components are:

• material colors
• textures
• light colors
• asset colors
• raw data values
  • roughness
  • intensities

Input color spaces can be set in Redshift’s texture node or the color picker for example.

Render Color Space

The working space of the renderer. This is usually a linear color space. Gamuts can vary from classic sRGB to wider gamus such as ACEScg. Most of rendering math is performed here, which require linear values.

Maxon Cinema 4D’s default render color space is ACEScg, a linear wide gamut color space.

View Transform

A color space transformation from render space to display space. This typically handles tone mapping from the HDR values coming from render space into the more narrow display space. Gamut compression can be part of the view transform too, for compressing the wide gamut render space into the smaller display gamut.

Examples are:

• ACES tone mapper
• AgX
• Filmic tone mapper

By default Maxon Cinema 4D uses the ACES tone mapper but can vary depending on the OpenColorIO configuration.

Display Color Space

The color space of the targeted display deliverable.

Typical spaces are:

• sRGB
• Rec.709
• Display P3
• Rec.2020
• Rec.2100 ST2084 or HLG for HDR

Currently only sRGB is supported by Maxon Cinema 4D’s inbuilt configuration. Loading external custom OpenColorIO is possible and allows extension of available display spaces. See description of the OpenColorIO Config parameter in the Color Management Settings section.

Monitor Profiles

Display monitors usually have a profile on the OS level that map colors into the native monitor color space. Most commonly these are ICC / ICM profiles but can also be hardware LUTs on the monitor itself.

Maxon Cinema 4D allows to toggle monitor profile support. This is especially useful for wide gamut or calibrated displays. There are toggles in the viewport, picture viewer and texture view.

Pros and cons

The new project wide OpenColorIO color management offers a few advantages over legacy ICC color management:

• OpenColorIO and ACES becoming the de-facto standard framework in most DCCs, thus allowing better compatibility across different DCCs, applications and 3rd party renderers.
• High customizability of used color spaces to fit into studio pipelines
• Out of the box “ACES workflow” to provide a smoother workflow in ACES pipelines. ACEScg OpenEXR images can be easily color graded and fit nicely into compositing workflows.
• Better support for HDR deliverables

There are of course a few disadvantages:

• No support for embedded ICC profiles in texture images. This might be crucial for some print oriented workflows for example.
• Switching from old to new color management requires color conversions. Scene results can differ when using colors as data, such as in MoGraph fields/effector.
• Since there is no out-of-the-box support of embedded color profiles some extra steps might be required by the user in the setup. There are some heuristics and automation in place to make that easier though.

Color Management settings

These are the new color management settings. there are located as usual in the Project settings.

• Change Render Space - This opens a dialog to change the render space. Think about the render space as the working space of your renderer. This is where all shading and rendering happens. Some spaces are better suited for certain tasks. This will be a bit detailed in the use case section.
• View Transform (Project) - This drop-down offers a few choices on how the rendered colors are transformed into your display space. Rendered colors are usually linear and often in the HDR range and need some kind of tone mapping. This is the place where you can choose between tone mapping or un-tone-mapped. The default Cinema color management configuration offers the ACES 1.0 SDR-video tone mapper here. It replicates typical motion picture contrast and tonality. The view transform is applied in all views such as Picture Viewer, Redshift Render View, C4D Viewport, C4D Texture View.
• View Transform (Thumbnails) - see above except it applies to the material thumbnails. Sometimes it makes more sense to display un-tone-mapped colors in the material thumbnails. This is the place to change that.
• Display Space - This is color space of your target display. Currently only sRGB is offered in the default configuration. With custom configurations other spaces could be offered to more precisely preview a deliverable on a compatible display. For example it could offer ST2084 HDR to preview HDR content on a compatible display.
• OpenColorIO Config - An advanced option to load custom OpenColorIO configurations as file or via the $OCIO environment variable. This allows studio pipelines to integrate Maxon Cinema 4D seamlessly. OpenColorIO configuration files can define custom color spaces for the use in the individual parts of the color management pipeline, for example extended display spaces support such as Display P3.
• OpenColorIO File Rules - OpenColorIO configurations allow to define rules to pick the right color space for individual asset files. For example a rule can define that EXR files always use ACEScg as their input color profile. The default configuration comes with a few rules that cover most common use cases.
• Info text - info text at the bottom informs about the current color management setup, which spaces are used and how colors are stored and interpreted.

Change Render Spaces

Clicking the Change Render Space button will open this dialog:

• Current Render Space - info text that indicates the current space
• New Render Space - a drop-down that offers the available render spaces. This can vary for different color management configurations. The default configuration offers these render spaces:
  • ACEScg - This is the default color space. It’s a wide gamut linear space which offers more leeway when working with saturated colors or lights. It can also produce more pleasing results when using indirect lighting. This is also the companion space for the ACES tone mapper and ACES workflow. Files saved in ACEScg are quite common as exchange format for VFX and compositing pipelines.
  • ACES2064-1 - This is a super wide gamut linear color space. It should only be used by experienced users that know about potential down-sides such as precision concerns or negative primaries. It’s mostly used as an archival space since it offers the widest range of colors.
  • scene-linear Rec.709-sRGB - sRGB and Rec.709 linear color space. This used to be the most common render space before ACES. It’s usually used either in un-tone-mapped renderings or with more traditional tone mapping, such as Reinhard, Exponential etc. Still valid, especially for stylized rendering or when certain input colors such as brand colors need to be retained. It has a rather small gamut which results in rather fast clipping, typically with saturated colors and lights.
  • scene-linear Rec.2020 - A linear color space if rendering directly in that HDR content related space is required. It’s rather special purpose though.
  • scene-linear DCI-P3 D65 - A linear special purpose color space for digital cinema. Mostly for these very rare specific use cases that need to render directly within that space.
• Convert Colors - This option defines if scene colors will be converted to retain their look when switching render spaces. Usually this should stay on. There are use cases where it might be turned off. The actual stored color values will stay untouched in this case. This can be sometimes useful to fix certain scenes or if merged scene elements came in from a known color space.

Clicking OK will convert between current and new render space.

Example use cases

The default settings of a new fresh scene has been picked for typical photorealistic rendering and best fit into VFX and compositing pipelines. Different use cases might require picking different settings. Some project templates will aid the user though. These templates are available via the Maxon Cinema 4D Home Screen and the Asset Browser. The Asset Browser location path is “Example Scenes->Features->C4D Home"

Photorealistic rendering

Photorealistic rendering often results in values outside the 0-1 range. These HDR values need to be tone mapped to be displayed properly on a typical display. ACES provides its own tone mapper for that purpose.

Another advantage of ACES is its wide gamut of the ACEScg render color space. This is beneficial when rendering with saturated colors and prevents early gamut clipping.

Often these renders go through external composition or color grading. Rendering out into linear 32bit OpenEXR ACEScg images will give the most flexibility in post production. Most composting software offers exactly the same ACES view transform (tone mapper) as Maxon Cinema 4D’s color management. This provides a non-destructive workflow with an accurate preview inside Maxon Cinema 4D.

Tone mapping and gamut compression will inherently alter input colors. This can affect and alter the reproduction of brand colors. It’s comparable to setting up a real physical scene and taking a picture with a camera.

The Redshift ACES template is best suited here.

Stylized and NPR rendering

Stylized and NPR rendering usually stays within the traditional 0-1 range of colors. It relies on an exact reproduction of the user input colors. It’s comparable to painting on a canvas.

Since the user basically interacts with exactly the same colors across the whole rendering process color space gamuts are not as crucial. Often it is sufficient to stay within sRGB/Rec.709 color space throughout the color management pipeline.

For the same reason tone mapping also plays a less important role and can be omitted in many cases.

Maxon Cinema 4D’s color management offers a full sRGB un-tone-mapped color management for this purpose.

Either Redshift Linear Workflow or Standard Linear Workflow template are best suited here.

Legacy scene conversion

Scenes that had been created with the old non-OpenColorIO color management are still loading and rendering as is. This is indicated as Legacy (sRGB linear workflow) in the Color Management project settings.

Depending on the used renderer there are a bit different behaviors how colors are managed. Please refer to the Status Quo prior R2026 section.

The user can choose to convert from Legacy to the new project wide OpenColorIO color management. Generally speaking this will not alter looks unless used color spaces and tone mapping differ.

Here are some examples with recommended steps and settings to convert from Legacy to new project OpenColorIO color management. These will make sure retain the look as much as possible.

Redshift

For Redshift the user essentially needs to match the old Redshift render settings to the new project based settings.

Standard and Physical Render were using ICC profile and sRGB based color management. Tone mapping was not part of the color management. The user needs to match the new project based color management to sRGB and un-tone-mapped.

Change Render Space dialog:

• New Render Space - scene-linear Rec.709-sRGB
• Convert Colors - On

Project settings Color Management:

• View Transform (Project) - Un-tone-mapped
• View Transform (Thumbnail) - Un-tone-mapped
• Display Space - sRGB

Color Chooser

The color chooser dialog has a slight different behavior between Legacy and OpenColorIO mode. Essentially with OpenColorIO a new Color Space drop-down is offered in the color chooser. This allows the user to edit colors in any of the offered spaces. This can be useful to enter linear or raw values directly.

Legacy mode chooser

 

OpenColorIO chooser. Note the new drop-down. By default it’s set to sRGB to provide a familiar experience. Setting it to ACEScg would allow entering linear values for example.