The Node Editor is used to work with node-based data-flows. More information about nodes can be found in the the Concepts chapter.
When opening the node editor, the document selection is automatically displayed. If nothing is selected in the document, the node editor starts with an empty canvas.
The toolbar is located on top of the node editor.
The following actions can be found in the toolbar:
- Graph document selection
- Graph relations (inputs and outputs) of the document selection
- Graph highlighted
- Graph relations (inputs and outputs) of all highlighted nodes
- Graph highlighted inputs
- Graph input relations of all highlighted nodes
- Graph highlighted outputs
- Graph output relations of all highlighted nodes
- Rearrange Graph
- Rearrange currently displayed nodes
- Show highlighted only
- Hide all non-highlighted nodes
- Add selected Nodes
- Add all nodes from the document selection. (Without dependencies. Only the selection itself is added)
- Clear view
- Remove all nodes (not delete) from the canvas
- Show/Hide the attribute editor
- Shows (on) or hides (off) the Attribute Editor on the right side of the node editor. The attribute editor can be used to edit values of the selected item. See the Attribute Editor chapter for more information.
The node editor makes a difference between selected nodes and highlighted nodes.
See the Node Selection section for more information.
Working with Nodes¶
Nodes can be highlighted with the mouse and moved by click-dragging on their header with the left mouse button.
The node editor makes a difference between selected nodes and highlighted nodes. selection refers to “selected items in the document” and highlighted to “selected in the node editor only. Depending on the state different styles are used to draw the node. The following image summarizes the style used for each of the possible states:
- To highlighted a node
- Click on it with the LMB. Multiple items can be highlighted with mouse clicks, if the Ctrl key is held down during the click, the item is added to to the list of highlighted items (similar to the selection of objects in the document view).
- Click-drag with the LMB a “rubber-band” around the items you want to highlight. In order to activate the “rubber-band”, the fist click must not be above an item.
- To select a node
- Double-click on it with the LMB. Multiple items can be selected with mouse clicks, if the Ctrl key is held down during the double-click, the item is added to to the selection.
- Click on a free space in the canvas to clear the highlight state for all items.
- Double-click on a free space in the canvas to clear the selection.
The purpose of a connection is to keep the value of the input plug in sync with the value of the output plug (therfore connections are always “directed”).
Despite connections between two plugs, the node editor also displays (and lets you edit them) “peudo-connections”. These are not connections between two plugs, but indicate:
- Relationships between transforms and transform and leaf
- A node is an input of a plug (that takes a node as input)
The following image summarizes all relation types shown as “connections”
To create a connection between two plugs, click-drag on the source plug and move the “wire” to the target plug, as shown in the following animation:
When moving over a (potential) target plug, the corresponding input handle indicates if a connection is possible: * Green indicates that a direct connection is possible * Red indicates that the types of source and target are not compatible, and no connection can be done * Brown indicates that a direct connection is not possible, but sub-elements can be connected. If the connection line is dropped on such a plug, the Attribute Connection Editor opens and lets you choose sub-plugs. For Green inputs, the Attribute Connection Editor can be triggered by holding the Shift key while dropping the connection line onto the target plug.
Sometimes, plugs take a certain node type as input (eg. the Exposure Map of a shape). In this case the data source is not a plug of a node, but the node itself. To place a node as input to a plug, the self output of the node can be used, as demonstrated in this animation:
Each output can drive an arbitrary number of inputs. However, sometimes it’s useful to move a connection from one input to an other. This can be done, by click-dragging on an existing connection:
Connections can be “broken” (deleted) with the Disconnect action, found in connections context menu. The menu can be activated with a right-click, while the mouse pointer is over a connection line.
Creating New Nodes¶
New nodes can be added in the node editor. To a a new node, click on the item type you want to add in the tree view on the left side.
Additionally the Duplicate Node action (found in the specialized Context Menu for nodes) can be used to make a copy (without connections) of a node. Click with the right mouse button on a node to activate the context menu.