The Group node wraps multiple nodes together but does not do any processing itself. It’s used for managing sets of nodes in large or complex graphs.
The Group node can be expanded, to modify its child nodes, or collapsed, to hide internal complexity. Left click the or icons in the top right of the node to expand or collapse it. When expanded, the title can be renamed so you have a better idea what the nodes inside of the group do.
Nodes can be added to the group by moving them over the dark region in the middle when the Group node is expanded. The dark region will turn yellow to indicate that the nodes will be added to the group. Connections from added nodes to other nodes outside of the group are maintained using pass through fields (see below). Group nodes cannot be added to other Group nodes.
Moving nodes inside of a group automatically resizes the group.
Nodes can be removed from a group by holding the Ctrl + Alt keys and moving the nodes outside of the group node.
Group nodes do not do any processing themselves but they do have pass through fields for connecting nodes outside of a group to nodes inside of a group. To add a pass through field, connect a child node to one of the unconnected anchors just left or right of the dark area in the Group node’s center. Similar to other nodes, pass through fields on the left are used for input and pass through fields on the right are used for output. Pass through fields can be renamed so that you remember what you are using them for. Pass through fields can be re-ordered or deleted by left clicking the up arrow, down arrow or X buttons.
Deleting a Group node will also delete all of its child nodes.
The Histogram node displays a graph built by counting how common tones are in an image. It’s usually used for managing color clipping.
See Histogram in Chapter 3. Essentials for more details.
- The image the histogram should be built from.
Which channel(s) should be displayed in the graph.
- RGB: Red, green, and blue channels.
- Red: Red channel.
- Green: Green channel.
- Blue: Blue channel.
- Luma: Y’ channel of the Y’UV color space as defined by NTSC.
How visible changes between values in the graph should be.
- Linear: Values are stretched equally so the overall trend is visible.
- Logarithmic: Values are stretched logarithmically so minor differences in the most common tones stand out.