modo bubbble logo

Color Management


Home >> Shade, Light & Render >> Color Management

back next

Color Management is a process that controls the conversion of colors when moving between different formats, systems and devices. The primary goal of Color Management is to maintaining accurate colors across the span of inputs and outputs. MODO's color management solution provides a straightforward user experience that is consistent with the functionality found in other Foundry applications. It is built using the academy award winning OpenColorIO technology, that is geared toward film and video production with an emphasis on visual effects and computer animation.

Color Management Overview

Color Management in MODO works by applying a 'Profile' to a color input. A 'Profile' is a set of instructions that describe colors relative to a known standard, and the 'color input' specifically would be color bitmap images imported into MODO (textures, backdrops, environments and so on). Based on the assigned 'Profile', the colors in the image are transformed to a linear 'colorspace' format for internal processing and rendering. A 'Colorspace' is a mathematical model that describes how colors are represented for a given format. Converting the bitmap image colors to a 'linear' colorspace ensures that image color fidelity is fully preserved during the rendering process.

The next part of the color management process is the output where rendered frames (still or animated) are then displayed in the Render Display window, where a destination transform is applied. The rendered image itself is stored in memory unaffected in the 'linear' format, with the transform applied non-destructively by the viewport using a LUT (Look Up Table) which is basically a predefined set of translation operations from one colorspace to another. This allows users to properly preview how the final image should look, without adversely affecting the actual rendered frame. This also allows the image to be saved linearly using a high dynamic range format for additional processing in another application further down the pipeline, ensuring continued color fidelity. For users where MODO is the final destination, colorspace transforms can be applied to the image when saving to a low dynamic range format for direct use or processing in a non-color managed application, retaining the look of the image from the Render Display window.

It should be noted that MODO ships with default Color Management settings that should work perfectly fine for most users without further adjustment. The following controls will likely only be edited by advanced users with specific needs. It can certainly be helpful to understand how Color Management works in MODO, but even for advanced users, it will be more of a "set it and forget it" type of situation once the proper settings are defined.

Tip icon

IMPORTANT: When using Color Management, it is no longer necessary to 'degamma' an image for rendering, this is handled automatically by the Color Management system. (Defaults for all 'Gamma' settings are now set to 1.0)

MODO Workflow

A Color Profile is assigned automatically to any RGB bitmap image imported into MODO (single channel grayscale images are always be treated 'linearly'). Determining which profile is assigned to which image type starts with the 'Color Management' settings found in the 'Preferences'. These values specify the initial, default settings assigned to a new scene. Changing them won't directly affect older scene definitions, nor will will they affect any scenes that are currently open. It simply determines the default values for newly created scenes.

When a new scene is created, users can access the scene-specific Color Management settings by selecting the Scene Item itself (topmost item in the Items List with the movie clapperboard icon). When selected, the following options are available in the 'Properties' panel-

Scene IO

With these settings, users can globally modify the Profiles for all images within the same scene using a single setting, instead of having to manually change each and every image. Of course, it's also possible to override this setting on individual images. This is done by changing the colorspace control on the Image Map item from 'default' (which means it References the 'Scene' item setting) to a specific colorspace. The setting is found under the 'Image Still' Properties subtab when the Image Map item layer is selected. Once defined this way, the image map will retain the setting regardless of changes to the Scene Item colorspace settings.

Once the proper colorspaces have been defined, processing for Color Management is all done in the background, and requires no further user input. The proper colorspace definitions allow modo to accurately convert from the source colors to a linear colorspace for internal processing and rendering. For image display, some users may need to adjust the 'LUT' settings present in the 'Preview' and 'Render Display' windows depending on monitor type; for most users the Default option should be fine as most monitors use the sRGB colorspace to display the output from the video card.

Saving Images will assign color Profiles using the same 'Scene' based Preference settings that are initially defined as the default value. When images are saved from the 'Render Display' window (or from 'Preview' window), the 'Colorspace' option from the bottom of the 'Image Processing' tab is the setting that controls which profile is assigned and embedded, should it ever be necessary to override the default value. Overrides can also be applied when saving rendered animations directly from a Render Output with the setting of the 'Render Output' itself. Both the Render Display control and the Render Output setting will normally be set to 'Default'; which Profile chosen will depend on the bit depth of the target format.

Tip icon

INFO: To ensure consistent rendering, MODO will open older scene files (pre-801) with 'Color Management' disabled. If Color Management is desired, users will need to manually enabled it for all items in the scene.

The following section explains all the specific controls for Color Management and where they are located in the interface-

Preference Settings

Found in the menu bar under "System > Preferences..." and then in the "Rendering > Color Management" section toward the bottom of the window, the Color Management Preference settings defines the default values that are inherited for any new scene that is created. Adjusting these settings won't affect older saved scene, or any open scenes.

Color Manage Prefs

Color Management--

Default OCIO Color Config: This option controls which configuration will be the default for new scenes, Each separate Config controls which color spaces are available for use by items in the scene. Each different Config contains a different set of Profiles. Users can also designate a Config for individual scenes manually, as an override in the Scene item.

Default 8-bit/16-bit/Float Colorspace: These options designate the scene default Profile assigned when reading and writing the associated bit depth of image for any Items that have their Colorspace control set to 'Default'. Users can also designate colorspace profiles individually on the Image Map item under the 'Image Still' subtab.

Default View Colorspace: This options defines the colormapping assigned to user interface elements, including the Color Picker, Color Swatches, the Render Display window and the interactive Preview. The 'Perform Color Correction on OpenGL Object' must be enabled in order to see the results of this setting on the 3D viewports.

Affect MODO Color Swatches and Picker: When this option is enabled, the 'Default View Colorspace' option will adjust the display of individual color input fields in the Properties form to match the colors of the Render Display.

Affect System Color Dialog: When this option is enabled, the 'Default View Colorspace' option will adjust the display of the Color Picker popups and Windows to match the colors of the Render Display.

 

 

Image Maps/Sequences

Image MapImage maps (and Image Sequences) that are loaded into the Shader Tree are assigned default Color Management Profiles based on the Scene Item settings. Users can override the settings, per image, based on the 'Colorspace' control in the 'Image Still' subtab of the Properties panel when the target Image map item is selected. The option illustrated here on the right are located in the 'Nuke-Default' Color Management config.

 

 

 

 

 

 

 

 

Render Outputs

Color OutputThe 'Output Colorspace' control in the 'Render Output' determines the particular color transform (if any) applied to images when saved out from MODO, either automatically by the Render Output when rendering an animation, or when saving from the 'Render Display' window. The Output Colorspace basically has three different ways it can be set, the 'None' option disables color management from affecting images when saved, 'Default' will automatically apply the color profiles defined by those set in the scene item, based on the bit depth being saved out from MODO. The third and last option is dependent on the color profile config defined in the Scene, but allows users to override the default colorspace value to a specific color profiles by defining one of the select color profiles available in the drop-down.

Working independently from the Render Output, there is the identical control available in the Render Display window, at the bottom of the 'Image Processing' tab, that will provide the same functionality as the this Render Output control.

 

Monitor Color Management

LUT

At the top of the Render Display window there is a 'LUT' setting (for 'Look Up Table') where users can specify their monitors Color Profile (not to be confused with the Render Output's Output Colorspace profile!). When working in a manged workspace this control allows users to easily swap Color Table configurations, say for instance if the Render Display is positioned on different monitors in a multi-monitor setup. For most users though, the default 'sRGB' setting should be fine as most computer monitors default to working within this colorspace.

Tip icon

TIP: Color Management can be completely disabled, where MODO will work as in previous version. This is done by setting the Color Management 'Preference' settings to 'None' and returning the default Gamma value in 'Preferences' to 2.2 prior to creating any new scenes. When this is done, users will need to manually degamma imported images for proper results (as in previous version of MODO).

 

comment balloon Comments (2) RSS Icon

Mike Jensen January 16, 2015 at 3:12 PM

Custom configs:
Modo supports custom OCIO configs. Placing your configuration and its associated LUTs in the resrc/ocio_configs folder within the application bundle (on Windows/Linux, or in Contents/Resources/ocio_configs on Mac) will result in it being available within the application, and allows complete control over colormapping operations.

For more information visit: opencolorio.org

xtof May 27, 2015 at 2:22 AM

I made a doka config with film-like response curves, among other things:

http://community.thefoundry.co.uk/discussion/topic.aspx?f=32&t=108920

Top

back next