Some Clean UP Work

• I am getting ready to move onto user interfaces.
  • We will do this with the course Your First Hour with UMG"
  • Assignment coming soon.
• Before that I want to look at some of the code in the starting game.
  • He uses the first person shooter.
  • And has health pickups.
• Pickups
  • He uses a hierarchy
    • A pickup base class
    • A number of derived classes
  • The derived classes are because we want to be able to talk to different things in different ways.
    • Ie, you pick up health, you do a health thing.
    • You pick up ammo, you do an ammo thing. ...
  • The parent class has
    • A static mesh component
      • This is changeable and represents different items.
      • (dot or +)
      • MeshToUse is a variable exposed where this is set.
    • A light
      • Light color is also exposed
    • A sphere collision, to trigger encounters.
  • The construction script
    • 
  • When play begins, it sets a random position between 0 and 5.
    • 
  • They built a timeline to make the object float up and down.
    • 
    • Notice, this is not triggered by any event.
    • But if you look in the timeline, auto play is set.
    • 
  • When the player overlaps

    • 
      OnCollision
          FloatingTimeline.Stop()
          PickupTrigger.destroy()
          Start Pickup Timeline
      
      
      
      On PickupTimeline.Tick()
          newLoc = NewMeshLocation(alpha)
          PickupMesh.SetWorldLocation(newLoc)
          scale = LERP(1,0.01, alpha)
          PickupMesh.SetScale(scale)
          intensity = LERP(5, 25, alpha)
          Light.SetIntensity(intensity)
      
      
      NewMeshLocation(alpha) 
           location = PlayerPawn.GetActorLocation()
           location += (0,0,40)
           newLocation = Lerp(PickupMesh.WorldLocation(), location)
           return newLocation
          
      On PickupTimeline End
         Call the member function OnPickedUp //(Event Dispatcher event) 

  • There are three pickups defined
    • Health and damage do about the same thing

      • 
        OnBeginPlay
            BindToEvent(OnPickedUp, PickupGrabbed) 
        
        
        PickupGrabbed
             Player.ApplyDamage()
             self.Destroy(); 

    • Apply damage calls an event
      • In this case, it is runs on the server in a multiplayer game.
    • Ammo
      • Does the same thing, but calls the blueprint interface Adjust Ammo
  • If we look at the Character_FirstHourUMG character, we can see corresponding functions.
  • Note the use of "Category" to organize the variables.
  • Take a look at Spawning a projectile.
  • Ok so how does it go away?
    • Actors have a value Initial Life Span
    • If this is 0, they are alive until destroy actor is called
    • If this is not 0, it sets the life of the actor.
    • It is set to 2 on the projectile.