Learn Phoduit

3.1.1 Graph

The Graph takes up the majority of the Main Window and it is where you will spend the majority of your time using Phoduit. The Graph is made up of nodes that are connected together to render your photo. Rendering just means Phoduit is doing the work needed to display or export your photo. As you modify the Graph (such as connecting nodes or adjusting sliders), Phoduit automatically figures out what has changed and performs the minimum amount of work required to re-render your photo.

Getting around the graph

As you add nodes and make larger graphs, it’s important to be able to navigate quickly. To pan the Graph, hold Ctrl and press the left mouse button anywhere in the Graph. As you move your mouse around, your view of the Graph will move with it. To finish panning, release the left mouse button. You can also move the Graph around using the arrow keys on your keyboard.

The Graph can be zoomed to show as much or as little as you want at a time. To zoom the Graph, hold Ctrl and scroll with your mouse wheel. Scrolling down zooms out and makes the Graph smaller. Scrolling up zooms in and makes the Graph larger. Zooming is performed relative to your mouse cursor’s location. For example, if you want to zoom in on a specific node, move your cursor over that node, hold Ctrl and scroll your mouse wheel up. You can also zoom using the keyboard shortcuts Ctrl++ to zoom in and Ctrl+- to zoom out.

If you ever have trouble finding the Graph because you panned it out of view, you can go to the “View” on the Menu at the top and click “Fit All Nodes” or press Ctrl+0 on your keyboard to automatically show all of the nodes.

Nodes

Nodes are the building blocks you use to change your photos into masterpieces. Each node does something specific to your photo which can be changed at any time for a completely non-destructive workflow. Some nodes only produce output, such as the Image Open node whose output represents an image you’ve imported into Phoduit. Some other nodes, like the Histogram node, do not produce any output but display information to help you reason about your changes. Most nodes take an image as an input, do some work on it, and then pass the processed image along as an output so another node can do further work on the image. By connecting nodes together, you have full creative control to produce unique photographs.

For a detailed description on a specific node and how to use it, see Chapter 9. Nodes.

Adding nodes

Nodes can be added to the Graph using “Node” on the Menu at the top or using the Nodes Toolbar.

You can also add supported JPEG, PNG, TIFF and raw photo files by dragging them from your file manager and dropping them over the Graph.

Selecting nodes

Nodes can be selected and moved around. To select a node, left click the node’s title bar. The node’s title bar and and border will turn yellow to indicate the selection. You can select multiple nodes at the same time by holding shift and clicking each node with your left mouse button.

To deselect a node, hold shift and click the selected node with your left mouse button.

To select a bunch of nodes quickly, you can use a selection box. To use a selection box, press Ctrl + Shift and click and drag with your left mouse button. Any nodes that intersect the selection box will be added to the current selection as indicated by the yellow border. Release the left mouse button to confirm the selection.

You might have noticed that when multiple nodes are selected, one of the nodes has a yellow title bar and the others do not. This is the node you are interacting with. Only one node can be interacted with at a time. Some nodes have special tools available when you interact with them such as the Paint Canvas node which lets you draw on the Canvas.

Moving nodes

Nodes can be moved around to keep the Graph organized. Keeping the graph organized is essential to making changes to your photos quickly. To move one or more nodes, select the nodes, move your cursor over the title bar of one of the selected nodes, press your left mouse button, drag your nodes to their new location, and then release your left mouse button.

Selecting and Moving NodesClicking a node’s title bar to select or move the node is similar to moving a window on your operating system. Unlike a window though, you can also click any area in a node that is not an anchor or a field (like a slider or button) for the same effect.

Deleting nodes

Deleting nodes is very easy. Select the nodes you want to delete and press the Delete key on your keyboard. Don’t forget that if you delete a node by mistake, you can go to “Edit” on the Menu and click “Undo” or press Ctrl+Z on your keyboard to undo the deletion.

Connecting nodes

To process a photo, you must connect nodes together. Specifically, the Render node must be connected to export your finished work. You connect nodes by clicking an anchor point on a node and dragging to the anchor point of another node.

An anchor is a little circle on the left or right side of a node. It changes color as it is used.

Anchor Description

Unconnected to any other nodes.

Connected to at least one other node.

You are currently interacting with the anchor.

Anchors on the left side of a node are known as Input Anchors and anchors on the right side of a node are known as Output Anchors. An Output Anchor must be connected to an Input Anchor and vice versa. Output Anchors can be connected to as many Input Anchors as you like but Input Anchors can only be connected to one Output Anchor.

Most nodes have both Input Anchors and Output Anchors with the node representing work being done on the input and producing the output. You chain nodes together by connecting the output of one node to the input of another to create complex and unique effects.

Disconnecting nodes

Sometimes you will want to move or remove a connection so you can try something different. To move or remove a connection, move the mouse cursor to the Input Anchor side of the connection, press the left mouse button down, then either move your cursor to another Input Anchor to move the connection or away from any Input Anchors to remove the connection, followed by releasing the left mouse button. This must be done on the input side of the connection because the Output Anchors support multiple connections and will always create a new connection instead.

Inserting nodes into connections

When two nodes are already connected to each other, there is a quick shortcut to insert a new node between them. Simply move the node you want to insert over the connection. The node must have an unconnected Input Anchor and an unconnected Output Anchor to be inserted. The connection will turn yellow if the node can be inserted.

Modifying nodes

Most nodes have settings that can be adjusted. Sometimes these settings are embedded as fields right in the node and other times you interact directly with the Canvas when the node is selected. You should see Chapter 9. Nodes for a detailed description on each node does and how to use them. However, special attention should be given to sliders because they are very common.

There are three types of sliders you should be familiar with. You interact with them all in the same way but they mean something differently.

Slider Description

A typical slider with a single “thumb” used to set a value within a bounded range. The thumb is an arrow that can be moved to represent a value within the bounded range of the slider.

A slider with multiple “thumbs” used to set one or more ranges of values within a bounded range.

A boundless slider which can be set to virtually any value and is usually only limited by available computing resources (processing time and memory).

Press with your left mouse button and drag your mouse to change a slider’s value. If the slider has more than one thumb, the thumb closest to the mouse cursor will be used. You can make more precise adjustments by holding the Shift key. To specify an exact value, click the slider with your left mouse button, type in a new value with your keyboard, and press the Enter key.

Rendering nodes’ output

You can turn the output of a node into a Paint Canvas node for pixel level editing without having to resort to compositing. Right-click the node’s output anchor, select “Render to” in the pop-up menu, and then left-click “Paint Canvas Node”. A dialog will be displayed to indicate rendering progress. Once rendering is done, a new Paint Canvas node containing the rendered output will be inserted into the graph.

This method breaks away from the non-destructive workflow that Phoduit encourages but it can be useful when working with masks that you expect to only refine manually through painting.