Doors

Door

We are going to create a door Parent that can be used to Open and Close any of the Child Events (remember the parent and child in Blender?)

Open your Content Drawer and in your Blueprints Folder, add a new folder called Doors

Open your new Doors Folder by double clicking it

then Right Click and add a New Blueprint Class

Select Actor

Name the new Blueprint BP_Door_Parent

Open it up by double clicking

Add a Static Mesh from the components tab on the top left and name it DoorFrame

Add a second static mesh and name it Door

Compile and Save

With your DoorFrame Component Selected, search for a door frame in the details panel under static mesh and select

Select your Door Component and search for a door in your details panel under static mesh

Move the door so that it fits in the doorway (You may turn off snapping if you want to be precision)

Compile and Save

Open the Event Graph for BP_Door_Parent

 Right Click and add a custom event and name it OpenDoor

Right Click and add a custom event and name it CloseDoor

Add a Timeline and call it DoorAnimation

Connect the Open Door event to Play

Connect the Close Door event to Reverse

Double Click on your DoorAnimation Timeline to open it up

Change the length to half a second 0.5

Click on the +Track and add a float track

Name it Door_Alpha

add Two keyframes (Right Click) 

Add the first on time 0  and value 0

Add the second on time 0.5 and 1

Select both Keyframes by shift click

Right Click  and select User

Compile and Save

Go back to the event graph and add the door component to the graph

Pull out a link from the Door Component and add SetRelativeRotation (door)

Connect Update

Pull out a LERP from New Rotation to rotate

Connect the Door Animation Timeline to the LERP Alpha and Check the Shortest Path Box 

Opening the Door

Child Blueprint and overlap

In the Blueprint for the Door Parent, select the Default Scene Root in the top left

The door is currently too small for the player to fit through so we need to increase the size

In the details panel  under transform, change the Y Value (Green) to 1.5 and the Z valuer (Blue) to 1.3

Open up your content drawer on the bottom left

Select your doors folder in Bluerprints

Right Click on the BP_Door_Parent

Select Create Child Blueprint Class

Name the Child BP_Door_Overlap

Double click to open it up

The goal is to get the door to open when we get close to it

To do this, we need to add a collision (just like we did with the lights)

Click on the +Add under components and add Box Collision

We will make the box collision pretty big so that we can get it to work at a distance

In the details panel, change the shape to X= 400 Y = 250 and Z = 200

Then move the box collision so it is around the door

Find collision in your details panel

Make sure Generate Overlap Events is checked and Collision Preset is on OverlapAllDynamic 

Find events on your details panel

We will create ab event by clicking the + On Component Begin Overlap

This will open up an Event Graph and add On Component Begin Overlap (Box) Node

Select the Box in your components and then Click the +  in Detail > Events > On Component End Overlap

You should now have two events on your event graph

One for begin (open) and one for end (close) when the player gets to the collision

In the begin node, pull out a link fr om Other Actor and add search for == to get the = Node

Right click on your Event Graph and add Get Player Character Node

Connect the return value  of the Get Player Character Node output to the Select Asset Input in the = Node

Add a branch

Connect the Output of the == Node to the Input Condition of the Branch

Connect the output Exec from the Begin Overlap to the input Exec of the Branch

What's happening here is that we are setting up the door to open when the character hits the collision box

From the Branch, pull out a connection from True and add Open Door Node

Copy and paste the Get Player Character, == and Branch Nodes then paste below

We are doing this so the door will not close if another Pawn (NPC) leaves the area. We want it to only trigger for the character.

Connect End Overlap Excec output to exec input of the new branch

Connect End Overlap other actor output (blue) to the unused input of the ==

From the branch connected to the End Overlap, pull out a new connection called Close Door

Select your work and create a comment called Overlap - Doors

Compile and save

Return to your FirstPerson Map Viewport

Open your content drawer

Drag your BPC_Door_Overlap in to your game

When you overlap (touch the collision box, your door should open

Pressure Plate

Creating an actor that will work as a pressure plate that will open a door

Open your content drawer and open doors folder then right click and create a new blueprint Class Actor

Name it BP_PressurePlate

Double Click to Open the Event Graph 

Add a static mesh component in the top left corner

Name it PressurePlate

 Select your PressurePlate Mesh and in the Details panel on the right side under static mesh, select cube

In the Details Panel under Transform > Scale, change the Z from 1.0 to 0.1

Compile

Add a Box Collision in your components (top left)

Make it fit around your pressure plate (like we did with the lights)

Look for Collision in your details panel

Make sure Generate Overlap Events is checked and Overlapalldynamic is selected in the presets

This makes anything that lands on top of the overlap will start an overlap event

Compile and Save

Under Events in the Box Details Panel, add the event On Component Begin Overlap

then select the box again and add the On Component End Overlap

(We have done this before)

**Important**

There is no Open Door Node in the Parent Class

We need to create a variable to deal with this

Create a new Variable and call it Door_Reference

In the details panel, change the variable type  to BP Door Parent

Set it as an Object Reference

This will allow you to set a level instance of a door and set it as a reference

Make sure to make the instance editable by checking the box so we can select a door in the world

Compile and Save

Drag out your door reference and choose Get

From your Door Reference Node, pull out and add Open Door

Connect the Exec from the Begin Overlap to the Exec to the Open Door Node

Drag the Box Collision in the graph (Get)

Add Get Overlapping Actors

Click on Class Filter and select Actor

What we are doing here is making sure that any actor is the one closing the door and not something that happens to fall on the trigger

We are creating an array (list of actors that are overlapping)

From the overlapping actors node, pull out the blue output for overlapping actors and select Get (a copy)

Pull out from the Output of your Get and select Is Valid? MAKE SURE YOU USE THE ?

From the Exec of the End Overlap Box, connect to the input of the ? Is Valid Exec

Change the GET # to 1

This will ignore the Zero Result (character) and checks for the next actor (cube)

From our Door Reference Node, pull out an add Close Door

Connect the Is Not Valid Exec to the Exec Close Door

So if an actor overlaps (collides) with the box collision. the door opens and only the actor will close the door

Compile and save

Go back to your First Person Map and Drag a Door (BP_Door_Parent)  in the game

Add a Pressure Plate and select it

In the Outliner Panel find Door Reference

Choose BP_Door_Parent

Compile, Save and Test

 Now we are going to move the pressure plate and set the blocks so that they will open the pressure plate without the character

Move the pressure plate in front of the three stacked cubes

Select the cubes

In the outliner on the right, look  for collision

Make sure Generate Overlap Events is selected 

Make sure Collision Presets is set to PhysicActor

Compile, save and shoot the box on the pressure plate to open the door