We now have a Cylinder in the world, as well as the Material we want to apply to the Cylinder when it is shot. The final piece of the interaction is the game logic that evaluates that the Cylinder has been hit, and then changes the Material on the Cylinder to our new red Material. In order to create this behavior and add it to our Cylinder, we have to create a Blueprint. There are multiple ways of creating a Blueprint, but to save a couple of steps, we can create the Blueprint and directly attach it to the Cylinder we created in a single click. To do so, make sure you have the CylinderTarget object selected in the World Outliner panel, and click on the blue Blueprint/Add Script button at the top of the Details panel. You will then see a Select Path window.
For this project, we are storing all our Blueprints in the Blueprints folder, which is inside...