Trace actions in a shooting situation
In this recipe we'll introduce the Trace action, which is very useful for testing whether the space between two actors is obstructed or unobstructed. The example we'll use continues from the last scene, where a wall drops down to reveal a Bot who wants to shoot at us. Being told to shoot at us, he does so regardless of the wall, which is not plausible, so adding the Trace will help with that.
Getting ready
Open Packt_04_SimpleTrace_Start.UDK or continue from where you were in the last recipe if you wish.
How to do it...
Open Kismet and, following the existing Actor Factory that provisions and spawns an enemy Bot, right-click and choose New Action | Misc | Trace. A Trace action draws a line between a Start object and an End object. You can also specify an exact HitObject it is looking for but in this case we don't need to. That would be more likely if you wanted to check against a NPC rather just a wall, which is what's getting in the robot's firing line...
