Preferences - Arnold for Cinema4d
The Arnold section in the Preferences window (Edit > Preferences...) contains global application level settings.
Arnold
Arnold in Main Manu Bar
When enabled, the Arnold plugin menu is added to the application menu bar as a separate entry.
When disabled, the Arnold plugin menu is under the Extensions menu.
Material
Default Material System
The default material system decides whether a Node Material or an old Arnold Material is created when creating an Arnold material from the plugin (e.g. Create > Arnold menu in the Material Manager, context menu in the IPR window, etc.).
Render Material Preview
When disabled, no Arnold material previews are rendered in the scene, either Arnold Material or Node Material.
Render Shader Previews
When disabled, no shader previews are rendered in an Arnold Node Material.
Viewport Preview
When disabled, Arnold materials are not displayed in the viewport, either Arnold Material or Node Material.
Default Preview Scene
Select the preview scene displayed when a new Arnold Material is created. Preview scenes have to be located in the application or user material preview folder (e.g. %HOME%\AppData\Roaming\MAXON\Maxon Cinema 4D R25_1FE0824E\library\materialpreview).
Default Shader Preview Scene
Select the preview scene displayed in the Node Editor when a new surface type shader is created. Preview scenes have to be located in the application or user material preview folder (e.g. %HOME%\AppData\Roaming\MAXON\Maxon Cinema 4D R25_1FE0824E\library\materialpreview).
Light
Viewport Preview
When disabled, Arnold lights are not displayed in the viewport.
Texture
Tx Generation
Tx is a tiled and mipmapped texture format, which will dramatically improve time to the first pixel, overall render time, and memory usage. Therefore converting textures to Tx files is highly recommended.
You can choose your preferred workflow of generating Tx textures:
none : No Tx files are generated, the original textures are used. Note that this mode is recommended is special cases only because it can hurt performance.
manual : Use the Tx Manager to generate Tx files manually when needed (e.g.original texture has been modified, color space has been changed, etc.). Existing Tx files are used in the render instead of the original images.
auto : Textures are automatically converted to Tx files before rendering the scene. Textures are converted from the image color space to the render color space. Each 8-bit texture is converted to 16-bit float data type images to avoid quantization errors in dark tones.
Info: Options passed to the maketx tool:
-u --unpremult --oiio (--colorconvert [image_space] [render_space] --colorconfig [config]) (--format exr -d half --compression dwaa)
Imager
Create Denoiser
When enabled, an Intel® Open Image Denoiser imager (OIDN) is added to new scenes by default.
Default LUT Folder
Select a folder which will be set as the LUT folder by default in a newly created tonemap imager.
Default LUT File
Select a LUT file which will be set by default in a newly created tonemap imager.
Color Manager
Default Color Manager
When enabled, the selected color manager will be set when a new scene is created or a new render settings is added to an existing scene.
Color Manager
Select the color manager added to the scene by default.
Cinema 4D Color Manager
Use color management settings from the Cinema 4D Project Settings (since Cinema 4D 2023).
default (ACES)
The default color manager implements the open-source OpenColorIO (OCIO) color management system and uses an OCIO v2 config shipped with Arnold. The color manager is configured to leverage the industry standard ACES color encoding system, setting the rendering color space to ACEScg.
Info: Find more information on the ACES workflow here.
legacy
This built-in color manager (the default color manager in Arnold 6) supports two color spaces:
sRGB
which corresponds to the sRGB colorspace with its corresponding gamma curve.linear
which corresponds to a linear color space with the sRGB gamut and white point.
This color manager is equivalent to the native color management in Cinema 4D.
OCIO
Through the ' color_manager_ocio
'
node Arnold can access color spaces defined in an OCIO config file.
Config
Path to the OCIO configuration file to use. If this is empty, OCIO will try to load the configuration file from the OCIO
environment variable. Alternatively, you can define $OCIO
explicitly, to use the environment variable.
sRGB color space (narrow)
If it exists in the OCIO configuration, this should be set to the name of the 'sRGB Gamma' color space. This is used internally for input and output color spaces in auto mode. If set by the user, this color space is also used as a reference to detect the rendering color space gamut and white point.
Linear sRGB color space
This is the default color space used on linear input textures which uses sRGB primaries. Typically HDR (high dynamic range) images, e.g. skydome or area light textures.
Render color space (linear)
This is the default linear color space that Arnold will use as its rendering color space. Arnold's default color space is ACEScg, but this can correspond to any linear color space if needed. If chromaticities for this linear color space can be guessed or are user-specified certain spectral effects will take them into account, but no other adaptations for albedos, transparencies, etc. are applied.
View Transform
Viewer devices (e.g. monitor, TV screen, etc.) have limited dynamic range and color gamut. To display the rendered image properly on these devices, it has to be transformed to the viewing color space (usually Rec 709 for TV and sRGB for web).
Bake View Transform Into Output
When rendering to the Picture Viewer or in Commandline or Team Viewer, Cinema 4D applies its native sRGB color transform, expecting the output to be in linear color space with sRGB primaries. That's not the case in Arnold when using a custom color manager (e.g. an ACES workflow with a custom view transform).
To get the correct output, this flag has to be set based on the image format we are targeting:
- Turn on the flag when saving to an 8/16-bit integer image (e.g. JPEG, PNG, etc.).
- Turn off the flag when saving to a 32-bit float image (e.g. EXR).
As opposed to the native workflow where you can save the rendered image from the Picture Viewer to any format, this flag must be set before rendering, defining the output format beforehand.
- If the flag is turned on and saved to an EXR, the image will be incorrect, because Cinema 4D applies an sRGB -> linear transform, yet the image is in the View Color Space instead of sRGB.
- If the flag is turned off and saved to a JPEG or PNG, the image will be incorrect, because Cinema 4D applies a linear -> sRGB transform, yet the image is in the Render Color Space (e.g. ACEScg) which is a wider gamut linear space.
Thumbnail View Transform
View transform applied to Arnold material previews.
Viewport
Legacy Viewport
Arnold objects, such as Arnold Procedural and Arnold Scatter, are displayed in the viewport via a fast GPU-based API. This option lets you fallback to the slower legacy viewport display in case of a failure. Requires restarting Cinema 4D to take effect.
System
DLL Search Path (Windows)
Third-party Arnold plugins (shader, procedural, volumes) can have DLL dependencies on Windows, which have to be loaded when using the given plugins in Arnold. List folders here which contains those DLL dependencies. Environment variables can be used (e.g. $MY_ENV_VAR
).