Operator
Object Hierarchy | Related C++ Class: Operator
Operator
v1.5
The Operator object represents an operator in the scene graph.
Objects or Parameters are connected to
the operator via InputPorts or
OutputPorts, which may be organized
into PortGroups. SDK users can create
their own operators, which are represented in the Object Model as
CustomOperators.
The responsibility of an operator is to change the output object
(or objects) with the result of some algorithm. The only data the
operator can read from the scene is via its input ports and
parameters. For example, a typical operator might change the
position of one object (the output) based on the position of
several other objects (the inputs). The same object may act as both
the input and the output of an operator, for example a typical
deformation operator will read a geometry and output a modified
version of the point positions of that same geometry. Selecting an
operator in the "SDK Explorer" view is a good way to learn more
about its ports and parameters.
To access individual ports from within the evaluation of a
Self-Installed Custom Operator use the OperatorContext object. From outside the
evaluation callback use the Operator.PortAt method.
Almost all Operators expose one or more Parameters which control the behavior of the
operator. For example, the "subdivu" and "subdivv" parameters on a
polygon mesh geometry operator control the number of polygons that
a polygon mesh is generated with.
The most common way to create and connect a built-in operator is by
calling the ApplyOp command.
However, there are many specialized commands for creating
operators, for example ApplyTopoOp, ApplyHairOp and ApplyGenOp. Operators are also
often created indirectly, for example calling X3DObject.AddGeometry creates an
operator that generates the geometry.
/*
This example illustrates how to generate a mesh by using the loft operator and
a number of input curves. The code also illustrates how to traverse the operator's
port group, port group instances and ports and logs the name of the port, its type
and the full path name of the object connected to the port.
*/
NewScene( null, false );
var arc = ActiveSceneRoot.AddGeometry( "Arc", "NurbsCurve" );
// Duplicate arc 4 times and translate in y
var args = new Array(19);
args[0] = arc; // source object
args[1] = 4; // number of copies
args[9] = siApplyRepeatXForm; // Xform
args[18] = 1; // Ty
var objs = Application.ExecuteScriptCommand( "Duplicate", args );
// Create array containing arc and duplicates
var aobjs = new Array(5)
aobjs[0] = arc;
for ( var i = 0; i < objs.count; i++ ) aobjs[i+1] = objs(i);
// Apply loft operator
var op = ApplyOp( "Loft", aobjs )(0);
// Traverse port group, instances and ports and log port connections
// For each port group ...
for ( var idxGroup = 0; idxGroup < op.GetNumPortGroups(); idxGroup++ )
{
// For each instance in a port group ...
for ( var idxInstance = 0; idxInstance < op.GetNumInstancesInGroup( idxGroup ); idxInstance++ )
{
// For each port in a port group instance ...
for ( var idxPort = 0; idxPort < op.GetNumPortsInGroup( idxGroup ); idxPort++ )
{
// Get a specific port
var port = op.PortAt( idxPort, idxGroup, idxInstance );
// If the port is an input port ...
if ( port.PortType == siPortInput )
porttypestr = "input"
else if ( port.PortType == siPortOutput )
porttypestr = "output"
else
porttypestr = "error"
var target = port.Target2;
// ... and the connected type is an object connection
if ( typeof(target) == "object" )
{
Application.LogMessage( op.Name + " group:" + port.GroupIndex + " " + " instance:" + port.GroupInstance
+ " " + porttypestr + "port:" + port.Index + ":" + target.FullName );
}
}
}
}
// Expected results:
//INFO : "Loft group:0 instance:0 inputport:0:arc.crvlist"
//INFO : "Loft group:0 instance:0 inputport:1:arc.kine.global"
//INFO : "Loft group:0 instance:1 inputport:0:arc1.crvlist"
//INFO : "Loft group:0 instance:1 inputport:1:arc1.kine.global"
//INFO : "Loft group:0 instance:2 inputport:0:arc2.crvlist"
//INFO : "Loft group:0 instance:2 inputport:1:arc2.kine.global"
//INFO : "Loft group:0 instance:3 inputport:0:arc3.crvlist"
//INFO : "Loft group:0 instance:3 inputport:1:arc3.kine.global"
//INFO : "Loft group:0 instance:4 inputport:0:arc4.crvlist"
//INFO : "Loft group:0 instance:4 inputport:1:arc4.kine.global"
//INFO : "Loft group:1 instance:0 inputport:0:surfmsh.kine.global"
//INFO : "Loft group:1 instance:0 outputport:1:surfmsh.surfmsh"
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