User guide

164
A Group Node Example
The following stand alone example produces a group node containing a network that produces a Scene Graph with
sphere and cube locations. It uses only Nodegraph API calls covered by this chapter. There is no access to the
generated Scene Graph from outside of the group node.
# Constants
TIME = 0
HALF_DISTANCE_APART = 1.0
# Create the group at root level
root = NodegraphAPI.GetRootNode()
group = NodegraphAPI.CreateNode('Group', root)
# Create the sphere at group level
sphere = NodegraphAPI.CreateNode('PrimitiveCreate', group)
sphere.setName( 'Sphere' )
sphere.getParameter( 'name' )\
.setValue( "/root/world/geo/sphere", TIME )
# Set the type to sphere
sphere.getParameter( 'type' ).setValue( 'sphere', TIME )
sphere.getParameter( 'transform.translate.x' ).\
setValue( HALF_DISTANCE_APART, TIME )
NodegraphAPI.SetNodePosition(sphere, ( -100, 100 ) )
# Create the cube
cube = NodegraphAPI.CreateNode( 'PrimitiveCreate', group )
cube.setName( 'Cube' )
cube.getParameter( 'name' ).\
setValue( "/root/world/geo/cube", TIME )
# Set the type to cube
cube.getParameter( 'type' ).setValue( 'cube', TIME )
cube.getParameter( 'transform.translate.x' ).\
setValue( - HALF_DISTANCE_APART, TIME )
NodegraphAPI.SetNodePosition( cube, ( 100, 100 ) )
# Create a Merge node at group level
merge = NodegraphAPI.CreateNode( 'Merge', group )
# Connect the two PrimitiveCreate nodes to a Merge node
mergeSphere = merge.addInputPort( 'sphere' )
mergecube = merge.addInputPort( 'cube' )
mergeSphere.connect( sphere.getOutputPort( 'out' ) )
mergecube.connect(cube.getOutputPort( 'out' ) )
# Rename our merge node to 'Result' to make it clear that
# this is the final result.
23 NODEGRAPH API | GROUP NODES