Month: May 2014

Originally posted on the Unreal Engine blog.

A Blueprint Macro lets you reuse a set of nodes over and over, and can be created in any blueprint (using the Add Macro button on the ‘My Blueprint’ toolbar). You can also turn a selection into a macro by right-clicking on a selected node and using the ‘Collapse to Macro’ option. A macro works a lot like a collapsed graph; you can define arbitrary inputs and outputs, which will show up as pins whenever you place a macro instance.  Here is an example of a macro named IsValid, which checks to see if an object pin is valid or not:

This macro can then be placed as an instance in another graph as ‘shorthand’ for the nodes it contains, allowing you to reuse code and hide complexity:

Continue reading “Blueprint Macros and Macro Libraries”

Originally posted on the Unreal Engine blog.

As you build larger projects with Blueprints, it’s easy to end up with an overwhelming sea of nodes.  However, we’ve built in a number of different encapsulation and code reuse mechanisms to help you battle the chaos.

To encapsulate something is “to show or express the main idea or quality of (something) in a brief way”; in other words we can hide a complex sequence of nodes with a simple stand-in that conveys the same meaning or idea.  You can still drill down and see how it works ‘under the hood’, but you don’t have to worry about the details when looking at the broader picture. Continue reading “Managing complexity in Blueprints”