3.7. Events and data enter and exit a composition through published ports

Earlier, you learned that a composition is made up of nodes, each of which is a building block that has a specific job to perform. If you think about it, the composition as a whole also has a specific job to perform. It’s like a node, but on a larger scale. A composition can even be used as a building block within another application.

Just as a node can input and output information through its ports, a composition can input and output information through published ports. If a composition has published ports, the Vuo Editor shows them in sidebars along the left and right sides of the composition canvas.

Above is an example of a composition with published ports: Generate Checkerboard Image (File > Open Example > Image Generators). It inputs events and data through published input ports called width, height, and time. It outputs events and data through a published output port called outputImage. If you run the composition in the Vuo Editor, it displays an animated checkerboard image. Because this composition has published ports, it’s also possible to run it inside of other applications, besides the Vuo Editor, that accept Vuo compositions. For example, you could use this composition within a VJ application to generate a stream of images that you’d mix with other video streams.