A Group node is a container that holds other nodes. Nodes can be grouped to help organize large, complex networks into more manageable units or to create customized node operations.
You can group any number of nodes (which can be "ungrouped" later if you wish) and modify individual node parameters and connections within the group node.
You can also customize the Group node itself by specifying which input and output connections from the nodes within the group to use on the Group node, as well as which node parameters to include in the Group Node Panel. This is described later in Customizing Group Nodes.
Here are some key points to remember when working with Group nodes:
You create a Group node by selecting one or more nodes in the Worksheet and choosing the "Create Group" command from the Worksheet Actions menu (right-hold in the Worksheet to access this popup menu.) The hotkey for the Group command is Ctrl-g .
The selected nodes are put in a Group node container, which appears in the Worksheet in place of the selected nodes.
All existing input and output connections to and from individual nodes are retained when the nodes are grouped, including any connections to external nodes (that is, to nodes outside the group).
Fig. 22.1 The Create Group command is selected from the Worksheet Actions menu to group the selected nodes.
You can also create an empty Group node by selecting Group from the alphabetical list of nodes in the popup Node menu. |
To "un-group" nodes, that is, to delete the Group container and return the nodes within it to the main level of the Worksheet, select the "Ungroup" command from the Node Actions menu (right-click and hold on the Group node to access). The hotkey is Shift-Ctrl-g .
When you create a Group node, you are effectively creating a multi-level Worksheet, in which the nodes within the group are one level down, or in, from the main Worksheet level. The node network in a RAYZ file can be thought of as a directory of nodes, with the Group node being a subdirectory containing the nodes within the group.
To access the contents of a Group node for editing, you need to display the Group node level (or "subdirectory") in the Worksheet. This is known as pushing into the Group node.
You push into a Group node by selecting the Push In command from the Node Actions menu (right-click and hold on the Group node to access). When you push into a group, the Worksheet view changes to display the nodes within the Group node.
When you are working within a Group node, select the Pull Out command from the Worksheet Actions menu to pull out of the group; that is, to go back up to the Worksheet level that contains the Group you were in.
Fig. 22.2 Main Worksheet level with Group node (top), and pushed into Group (bottom).
The title bar of the Worksheet view always displays the current level. At the top level, for example, the title bar would read "/project1" but when pushed into a Group node, the title bar would update to read "/project1/group1" (assuming that the Group node was named "group1").
Nodes can be grouped to create a customized node, with a unique set of parameters available in its Node Panel, which can then be used like any other single node. This is especially helpful when you have used a combination of several nodes to create a particular effect that may need fine-tuning or is likely to be reused with other imagery.
If you group the nodes, rather than switching from node to node to adjust different parameters, you can add individual parameters from each node to the Group Node Panel where they can all be viewed and adjusted together.
When you create a Group node, the Group Node Panel is blank except for the Define/Edit Group Parameters button. Two methods are available for adding node parameters to the Group Node Panel:
The panel is easier to use for comprehensive customization, however, if you are already pushed into the Group and know that there are only one or two parameters you need to add to the Group Node Panel, the export hotkey might be the fastest, easiest way.
Press the Define/Edit Group Parameters button in the Group Node Panel to bring up the parameter editor. By default this panel lists every node parameter in the group, organized by node, in the left pane. Check any parameter to add it and a corresponding entry will be created in the right pane.
The entries in the right pane enable you to organize how the parameters will appear in the Node Panel. You can reorder and rename them.
Fig. 22.3 All nodes in Group are listed in the left pane. The Translate (in Transform node) and Brightness (in Brightness node) parameters have been added to the Group parameter list in the right pane.
To add a spare parameter to the Group Node Panel, press the Add Spare Parameter button in the lower left corner of the Parameter Editor.
As with any other parameter you add, an entry will appear in the right pane. You can give the spare parameter an appropriate name and expand it to access setup parameters.
Fig. 22.4 Expand the spare parameter entry to specify default value and range. You can also give the parameter a more expressive name.
Spare parameters can be used to create a master, or gang, control for other parameters by using an expression to reference the spare parameter in the other parameters.
For example, if you had several Brightness nodes that performed the same operation on a different input, you could name the spare parameter "Master_Brightness" and reference it in the Brightness node parameters. Then when you adjusted the Master_Brightness value, all of the Brightness parameters would update accordingly.
You could use clones of a Brightness node for this purpose, but the other Brightness node parameters could not be set separately the way that they can when a spare parameter is used.
Another advantage of using a spare parameter is that, unlike using clones, you can still modify each Brightness parameter individually if necessary: one Brightness expression could reference the spare parameter value as is, another could multiply it by 0.8, and another by 1.2. All the Brightness nodes would change proportionally when you adjusted the Master_Brightness parameter, although each would have a different numerical value.
When you push into a Group node and assign a parameter in a node to the Group Node Panel, you are "exporting" the parameter. Follow these steps:
To see the result, pull out of the group and select the Group node to display its Node Panel. You still have the option of opening the parameter editor if you want to rename the parameter or make other adjustments.
Like other types of node, a Group node must be connected to other nodes in a network in order to modify those nodes or be modified by them. When the Group node is created, it is given only as many input and output connectors as necessary to maintain any existing connections between the nodes within the group and other nodes in the network.
If you need to make additional connections, however, you can export the input and output connectors of nodes within a group so that they too appear on the Group node. In this way you can make new connections to and from the Group node after it is created.
A truncated connection line will appear to indicate that the connection has been exported, and when you pull out of the group, an additional input or output connector will appear on the Group node. For this reason, Group nodes can have multiple output connectors.
Fig. 22.5 This view of the Worksheet (pushed into a Group node) shows input and output connectors that have been exported from the Group.
You can create a layout with two Worksheets so that one can display the main level node network while you use the other Worksheet to push into the group node. |
Input connectors are labeled with the initial of the node to which they connect. For more detailed information about any connector on a Group node, mouse over the connector. The name of the internal node and the type of connector (reference input, garbage matte, etc.) will be displayed in the Status bar.
Fig. 22.6 Position the cursor over any input or output connector to get information about the connection in the Status bar.