Key Locations


The /root group is located at the top of the hierarchy and contains collections, output settings, and global render settings. Most of these attributes are not inherited.

Type Attribute Description
group <renderer>GlobalStatements This defines global renderer-specific settings and has a different name depending on which renderer is used, for instance prmanGlobalStatements, arnoldGlobalStatements, and similar.
string collections.<name>.cel The CEL statement for a named collection.
string[] collections.<name>.baked A list of scene graph location paths baked from the CEL statement of a named collection.

Render Settings

Type Attribute Description
string renderSettings.cameraName The scene graph location of the camera; for example, /root/world/cam/camera.
string renderSettings.renderer The name of the renderer plug-in to use when starting a render; for example, prman
string renderSettings.resolution The render resolution preset, for example, 512sq.
float[4] renderSettings.overscan Overscan value in pixels, in the order: left, bottom, right, top.
string renderSettings.adjustScreenWindow The method for auto-adjusting the pixel ratio.
int renderSettings.maxTimeSamples Defines how many times a point is sampled when the shutter is open.
float renderSettings.shutterOpen renderSettings.shutterClose The timing of the opening and closing of the camera shutter. The shutter begins opening at t=0, and finishes opening at shutterOpen. The shutter begins closing at shutterClose, and finishes closing at t=1.
float renderSettings.currentTime The time of the frame for which the scene has been cooked, as set in the timeline of the Katana main window.
float[4] renderSettings.cropWindow The render crop window in normalized co-ordinates, in the order: xmin xmax ymin ymax.
string[] renderSettings.interactiveOutputs Indicates which outputs (as defined in renderSettings.outputs) to use for interactive renders (Preview and Live Renders).
int renderSettings.producerCaching.limitProducerCaching Controls how the Katana procedural caches potentially terminal scene graph locations.

Pass Settings

Type Attribute Description
group renderSettings.outputs.<passname>

Contains a sub group for every render pass. The default pass is named primary.

The rendererSettings/locationSettings are configurable per output. Output types are customizable by plug-ins. For instance, a color output has different rendererSettings than a shadow output.

string renderSettings.outputs.<passname>.type The type of output.
string renderSettings.outputs.<passname>.includedByDefault When enabled, this render definition is sent to the Render node.
string renderSettings.outputs.<passname>.rendererSettings.colorspace The color space.
string renderSettings.outputs.<passname>.rendererSettings.fileExtension The file extension of the output file.
string renderSettings.outputs.<passname> The channel of the output file.
group renderSettings.outputs.<passname>.rendererSettings.convertSettings Attribute group with file format-dependent conversion settings.
int renderSettings.outputs.<passname>.rendererSettings.clampOutput Post-render, clamps negative RGB values to 0 and alpha values to 0-1.
int renderSettings.outputs.<passname>.rendererSettings.colorConvert If 1, converts the rendered image data from linear to the output colorspace specified in the filename post-render. The colorspace is determined by OCIO’s parseColorSpaceFromString() function, which locates the longest, right-most colorspace substring.
string renderSettings.outputs.<passname>.rendererSettings.cameraName Scene graph location to render from.
string renderSettings.outputs.<passname>.rendererSettings.locationType The type of location.
group renderSettings.outputs.<passname>.rendererSettings.exrheaders List of EXR headers to inject.
string renderSettings.outputs.<passname>.locationSettings.renderLocation The file path and name of the output.


This group defines attributes that are inherited by the whole world, for instance, geometry, cameras, or lights. Some attributes like the lightList are inherited further down the hierarchy; others like globals, however, define universal settings and are not inherited.

Camera and Light Lists

Type Attribute Description
string[] globals.cameraList The list of scene graph locations of cameras; for example, /root/world/cam/camera and /root/world/cam/camera2.
group lightList.<entry> A sub-group for every light and light filter; for example, lightList.root_world_lgt_gaffer_light1.
string lightList.<entry>.path Scene graph location of the light or light filter, for example, /root/world/lgt/gaffer/light1.
int lightList.<entry>.enable Defines whether the light or light filter is enabled.
string lightList.<entry>.type Type of light list entry, either light filter or light filter reference. If this attribute is not set, the entry is assumed to be for a light.
string lightList.<entry>.inherits For light filters only - the scene graph location this light filter should inherit its attributes from.
string lightList.<entry>.referencePath For light filter references only - the scene graph location this light filter reference should inherit its attributes from.
string globals.coordinateSystems.<name> Defines a new co-ordinate system at the specified scene graph location.
string[] globals.itemLists.<custom> Defines a custom item list. When node graph subtrees are merged via a Merge node, the contents of item lists are unioned rather than the left-most input being used.


Top-level group for geometry.


Top-level group for cameras.


Top-level group for lights.


Top-level group for materials