User guide

8 Scene Graph Generator Plug-
Ins
Katana's operation revolves around two graphs: the Node Graph and the Scene Graph. To reiterate, here are some
of Katana's key concepts as described in the Katana User Guide:
Within the Node Graph tab, Katana utilizes a node-based workflow, where you connect a series of nodes to read,
process, and manipulate 3D scene or image data. These connections form a non-destructive recipe for processing
data. A node's parameters can be viewed and edited in the Parameters tab.
To view the scene generated up to any node within a recipe, you use the Scene Graph tab. The Scene Graph's
hierarchical structure is made up of locations that can be referenced by their path, such as /root. Each location has a
number of attributes which represent the data at that location. You can view, but not edit, the attributes at a
location within the Attributes tab.
Katana provides a dedicated C++ API for writing Scene Graph Generator (SGG) plug-ins that can be used to
dynamically create entire hierarchies of locations in the Scene Graph, containing arbitrary attribute data at each
location.
It is important to note that an SGG plug-in can only create locations and attributes underneath a single scene graph
location, its root location, and that an SGG plug-in does not have access to any other part of the scene graph. The
main purpose of an SGG plug-in is to create scene graph locations and attributes from external sources while being
controlled by certain parameters.
Scene graph generator plug-ins can be regarded as equivalent to procedurals in renderers, and can be used for a
variety of purposes, for example to implement an importer for a custom geometry file format or to generate
procedural geometry such as debris from particle data.