User guide

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These requirements are broadly similar to Python's naming rules. For more information, refer to
https://docs.python.org/2/reference/lexical_analysis.html#identifiers.
Common Attributes
Attributes in the hierarchy can make use of inheritance rules. If an attribute isn't set at a location, it can inherit the
value for that attribute set at a parent location.
The /root location holds settings needed by the renderer, such as flags to be passed to the command that launches
the renderer, or global options. Common settings for any renderer include:
• renderSettings.renderer
Which renderer to use.
• renderSettings.resolution
The image resolution for rendering.
• renderSettings.shutterOpen and renderSettings.shutterClose
Shutter open and close times for motion blur (in frames relative to the current frame)
Depending which renderer plug-ins you have installed, you will also see renderer specific settings such as:
• prmanGlobalStatements
For Pixar's RenderMan specific global settings
• arnoldGlobalStatements
For Arnold specific global statements
Collections defined in the current project are also held as attributes at /root, in the collections attribute group.
By convention attributes set at /root are set to be non-inheriting. In Katana /root/world is used as the base location
of the object hierarchy, where you can set default values you want inherited by all objects in the scene.
Common attributes at any location in the world hierarchy include:
• xform: the transformations (rotation, scale, translate, or homogenous transformation matrices) to be applied at
this level in the hierarchy.
• materialAssign: the path to the location of any material to be assigned at this location in the hierarchy.
• Renderer specific, per-object, options such as tessellation settings, and trace visibility flags. These are held in render
specific attribute groups such as prmanStatements and arnoldStatements.
Common attributes at geometry, camera, and light locations include:
• Vertex-lists, UV co-ordinates, and topological data.
For geometric objects.
• FOV and projection type.
7 SCENE ATTRIBUTES AND HIERARCHY | COMMON ATTRIBUTES