OpenNI 1.5.7
Glossary


Generator Class

A class derived directly or indirectly from the @ref xn::Generator class.

Generator Node

A node instantiated and created from any one of the @ref dict_gen_class 
"generator classes". 

Node Alternative

Any existing (already created) node or plug-in that satisfies an 
enumeration query. The nodes are checked first. 

See also @ref create_method

Frame Objects

A @ref dict_gen_node "generator node's" metadata object is a frame 
object containing a saved data frame from the node, and all the data 
frame's associated properties. For example, a DepthMetaData object is 
for containing a depth map 'frame object' from the DepthGenerator node. 

In principle, an application can save a number of frame objects, each 
in a different metadata object. 

The frame data can also be accessed directly from the generator node -
by using the node's @ref xn::Generator::GetData() "GetData()" 
method. 

Thus:
@verbatim
    metadata == frame object { <br>
       frame data <br>      
       frame configuration <br>
    } <br>

    generator 'outputs =>' frame object == frame configuration + frame data <br>
    <br>
@endverbatim

This means that a @ref dict_gen_node "generator node" outputs the frame 
object, and the frame configuration is copied from the original 
configuration at the time of the generation of the frame object.

Typically: 
@verbatim
    current configuration = frame configuration
@endverbatim

For more detailed information about frame objects, see @ref conc_meta_data.

Frame Data (Data Frame)

The map generated from the node. This map is contained in the node's 
@ref glos_frame_object "frame object". 

Frame Configuration

The frame configuration associated with a generated @ref frame_data "data frame". 

Holder Node

The term 'holder node', is used in regards to a capability object. The 
'holder node' is the production node that a particular capability object 
is associated with. 

Meanings of 'User'

This document uses the term 'human user' when referring to the human 
user seen by the sensor. The term 'user' refers to OpenNI's internal 
representation of human users that are pre-calibration or are being 
calibrated. The term 'skeleton' refers to skeletons that are, by 
definition, after calibration. The term 'skeleton' refers to the 
on-screen graphic representation of the skeleton. 

Updating Nodes

'Updating' a node means that the node puts new data in its application 
buffer so that the application can access it. 

On updating a node that did not have new data generated, the available 
@ref glos_frame_object "frame object" remains the same. 

The application can access a node's data by calling the node's @ref 
xn::Generator::GetData() "GetData()" method. 

If a node has an associated metadata object, an application can access 
the node's data through the metadata object by calling the node's 
<code>GetMetaData()</code> method, e.g., @ref 
xn::ImageGenerator::GetMetaData() "GetMetaData()".