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addMetadata [-channelName string] [-channelType string] [-indexType string] [-scene] [-streamName string] [-structure string]
addMetadata is undoable, queryable, and NOT editable.
Defines the attachment of a metadata structure to one or more selected
objects. This creates a placeholder with an empty metadata Stream for
later population through the editMetadata command. It's similar
in concept to the addAttr command for nodes - a data description
is added but no data is actually set.
When assigning a metadata structure you must specify these flags
- channelName is the metadata channel type (e.g. "vertex"),
streamName is the name of the metadata stream to be created,
and structure is the name of the structure type defining the
contents of the metadata. The indexType flag is optional.
If it is not present then the index will be presumed to be a standard
numerical value.
You can query metadata information at a variety of levels. See the
table below for a full list of the queryable arguments. In each case
the specification of any of the non-queried arguments filters the list
of metadata to be examined during the query. For all queries a single
object must be selected for querying.
For example querying the channelName flag with no other
arguments will return the list of all Channel types on the selected
object that contain any metadata. Querying the channelName flag
with the indexType flag specified will return only those
channel types containing metadata streams that use that particular
type of index.
- Query the channelName flag to return the list of any channel types
that have metadata.
- Specify the channelName and streamName flags and query the
structure flag to return the name of the structure assigned to the
given stream (if any).
- Specify a channelName and query the streamName to return
the list of all streams assigned to that particular channel type.
- If you query the streamName without a specific channelName
then it returns a list of pairs of (channelName, streamName) for all metadata
streams.
Flag Combinations:
ChannelName IndexType StreamName Structure Create Can Query
0 0 0 0 X ChannelName, StreamName, Structure
0 0 0 1 X ChannelName, StreamName, IndexType
0 0 1 0 X ChannelName, Structure, IndexType
0 0 1 1 X ChannelName, IndexType
0 1 0 0 X ChannelName, StreamName, Structure
0 1 0 1 X ChannelName, StreamName
0 1 1 0 X ChannelName, Structure
0 1 1 1 X ChannelName
1 0 0 0 X StreamName, Structure, IndexType
1 0 0 1 X StreamName, IndexType
1 0 1 0 X Structure, IndexType
1 0 1 1 (a) IndexType
1 1 0 0 X StreamName, Structure
1 1 0 1 X StreamName
1 1 1 0 X Structure
1 1 1 1 (b) X
(a) Assign an empty metadata stream with default index type
(b) Assign an empty metadata stream with the named index type
| string[] | List of nodes to which a new Stream was successfully added (create mode) |
| string[] | List of channel types containing metadata on an object when querying the channelName flag |
| string[] | List of stream names on an object when querying the streamName flag |
| string[] | List of structures used by an object's metadata Streams when querying the structure flag |
| string[] | List of index types used by an object when querying the indexType flag |
In query mode, return type is based on queried flag.
metadata, component, stream, channel, association
applyMetadata, dataStructure, editMetadata, getMetadata
channelName, channelType, indexType, scene, streamName, structure
Flag can appear in Create mode of command
|
Flag can appear in Edit mode of command
|
Flag can appear in Query mode of command
|
Flag can be used more than once in a command.
|
polyPlane -n p -ch off;
select -r "pShape";
dataStructure -format "raw" -asString "name=IdStruct:int32=ID";
dataStructure -format "raw" -asString "name=OffStruct:float=Offset";
dataStructure -format "raw" -asString "name=OrgStruct:float[3]=Origin Point";
addMetadata -streamName "IdStream" -channelName "vertex" -structure "IdStruct";
addMetadata -streamName "OffStream" -channelName "vertex" -structure "OffStruct";
addMetadata -streamName "OrgStream" -channelName "edge" -structure "OrgStruct";
addMetadata -streamName "VFStream" -channelName "vertexFace" -indexType "pair" -structure "OrgStruct";
// Query for the list of all channel types possessing metadata
addMetadata -query -channelName;
// Return: edge vertex vertexFace //
// Note that in Mel to query by name you can use an argument of "True" as
// the channelName to indicate that it is the flag being queried. (Otherwise
// the MEL interpreter would think that your object name is the channelName.)
addMetadata -query -channelName "True" "pShape";
// Return: edge vertex vertexFace //
// Query for the structure assigned to a specific stream
addMetadata -channelName "vertex" -streamName "OffStream" -query -structure;
// Return: OffStruct //
// Query for the list of all streams on a specific channel type
addMetadata -channelName "vertex" -query -streamName;
// Return: IdStream OffStream //
// Query for the list of all streams
addMetadata -query -streamName;
// Return: IdStream OffStream OrgStream VFStream //
// You can combine queries to answer more general questions about the
// metadata on an object. For example suppose you wanted to know the
// index type used by all Streams on the "vertex" Channel.
// First extract the list of Streams on the Channel
string $streams[] = `addMetadata -channelName "vertex" -query -streamName`;
int $i;
// Loop through each Stream, querying the IndexType only for that Stream
for( $i=0; $i < size( $streams ); ++$i )
{
string $indexType = `addMetadata -channelName "vertex" -streamName $streams[$i] -query -indexType`;
print ( "Index type on " + $streams[$i] + " is " + $indexType + "\n" );
}