We are nearly ready to place all of our pieces in the game world. Before we do that we need to create the aforementioned custom collision channel. We can do this via Project Settings. Navigate to Edit | Project Settings. Once there, navigate to Engine | Collision. This will present you with a settings menu with two categories ObjectChannels and TraceChannels. We are going to be adding a new object channel. This can be done by pressing the NewObjectChannel button, which will present you with this wizard:
With this wizard create a new channel called BMCharacter with a default response of Block. This channel is the one we are going to be setting as the collision type on our FPCharacter. As this is the first custom channel we have created, the ECC_GameTraceChannel1 enum will resolve to this channel and our sweep test will only pick up collisions with objects that have set BMCharacter to be their collision type.