A basic Blueprint Example

• I started with a First person Shooter.
• I deleted all of the extras from the scene.
• Lets build a box, an that
  • Has a light that changes state when it is hit or run into.
• I created a new actor class blueprint called BP_Target
  • Add a component
    • collision box
    • Box
    • Light
  • Note I can move these in relationship to each other if I wish.
• Let's add two variables
  • Both integers.
  • hitCount and collisionCount
  • I need to compile then I can set a default value.
  • Note, I could also set a default value in the constructor script
• Let's select the Trigger and add an event handler.
  • Start by just adding a print string to say "I was hit"
  • Notice there are options (drop down menu in printString) that allow you to change some things.
• The Print String message fades fast, but note it is sent to a log.
  • Notice under Window, Developer Tools you can turn on the print log.
  • This is nice, you can see it a bit longer.
• Let's make it so I can turn the ligt on and off.
  • We will do this with Set Visibiltiy
  • But I will need a boolean to control this.
  • So make a new boolean variable.
  • And add a not node.
  • Set Light On
  • Wire this into the SetVisibility node too.
  • 
  • Note, by clicking in the center of the get node I can turn "watch" on and off
• Select all of these nodes, right click and select "Collapse to Function"
  • I had originally made this a macro but decided to promote this to a function. Please ignore macro pictures, it is a function
  • Rename this function Toggle Light
  • I connected the flow of control to the output.
• Let's add a function as well.
  • This will increment a counter for us.
  • Add a ++ node
  • Click and select Collapse to Function
  • Add a input parameter (Counter)
  • Mark this as Pass By Reference
  • Pipe Send this into the ++node
  • ?
• 
• Go back and add an On Actor Begin Overlap Event.
• Add a macro that prints the total hits and collisions.
• 
• Add a function that does the same.
• 
• 
• Let's add a blue print to the level.
  • Add a sphere and a collision sphere to the world.
  • I renamed this LevelSphere.
  • With the LevelSphere selected, edit the level blueprint.
  • Select OnActorBeginOverlap
    • Note, this is for the LevelSphere
  • Get actor of class, note I want the BP_Target class.
    • This is ok since I only have one.
    • It would be a problem if I had multiples.
  • From this Toggle Light
    • Note, this is a member function of BP_Target
    • You can call functions but not macros
  • From This Increment Count
    • Probably bad software design.
    • Declare a world variable World Sphere Collisions
    • Increment this.
    • And print it out.
  • 
• I would like to build a subclass of the light.
  • So click on BT_Target and select Create Child Blueprint Class
  • I called this BP_MultiColorTarget
  • I exposed the inherited member data so I could see Light On.
  • I Only want to execute this code when the light is on so
  • 
  • I built an array of light colors
  • 
  • And an index
  • And used those to set the new color for the light.
  • 
  • Then incremented the index with wrap
  • 
  • 
  • Overall, a bit of a mess but not too bad.
  • And If I were to add functions ...