The Node Graph

The Node Graph (often called the Node Tree or the Flow) is the infinite canvas occupying the lower half of the Compositor Workspace. This is where you construct your visual effects.

Anatomy of a Node

A node is a graphical block that represents a specific operation (e.g., Blur, Transform, Merge, ColorCorrector).

Every node possesses inputs and outputs:

  • Inputs (Triangles): Located on the top or sides of the node. This is where data enters the node.
    • Yellow Triangle: Background image input.
    • Green Triangle: Foreground image input.
    • Blue Triangle: Mask/Effect Mask input.
  • Outputs (Squares): Located on the right side of the node. This is where processed data exits the node to be passed to the next tool.

Adding Nodes

To add a new node to your graph, press Shift + Spacebar. This opens the Quick Search menu. Type the name of the tool you want (e.g., "Glow") and press Enter.

Alternatively, you can drag nodes directly from the Effects Library panel on the left side of the screen.

Connecting Nodes

To process an image, you must connect nodes together using pipes.

  1. Click and hold the square output of the first node (e.g., MediaIn1).
  2. Drag your cursor to draw a pipe.
  3. Release the cursor over the yellow triangular input of the second node (e.g., ColorCorrector1).

The image data will now flow from MediaIn1, through the ColorCorrector1 node, and out the other side.

Auto-Insertion

If you already have a pipe connecting two nodes, you can quickly insert a new node between them:

  1. Hold the Shift key.
  2. Drag a new node directly over the existing pipe until the pipe highlights in blue/yellow.
  3. Release the mouse. The node will snap into place, automatically connecting its input and output.

Navigating the Graph

As your composition grows to include dozens or hundreds of nodes, you must navigate the canvas efficiently.

  • Pan: Click and hold the Middle Mouse Button (scroll wheel) to drag the canvas around.
  • Zoom: Scroll the Middle Mouse Button to zoom in and out.
  • Fit to Screen: Press Ctrl + F (Windows) or Cmd + F (macOS) to scale the graph so all nodes are visible.

The Viewers

Building a complex node graph is useless if you cannot see the results. The top half of the Compositor Workspace features two Viewer screens.

  • Select any node in your graph and press 1 to display its output in the Left Viewer.
  • Select any node and press 2 to display its output in the Right Viewer.

This dual-viewer setup allows you to view your raw, unprocessed green screen footage in Viewer 1, while simultaneously looking at the final keyed composite in Viewer 2.