[unreal] key to open the door blueprint notes

【 Unreal Engine 】UE4 Automatic door and manual door opening blueprint teaching
Use the previous automatic door opening logic .

Press the specified key , Open door .
The principle is ： Game player F build —— Player collision detection —— If the player overlaps with the box shaped collision of the door —— Open door
There are two technical points involved ：

• Blueprint communication —— Player blueprint detected door , Tell the door blueprint to execute the opening event .
• collision detection —— Keystrokes , Traverse the objects that players collide , If there is a door , Then execute communication .

One 、 Establish blueprint communication

Blueprint interface —— Blueprint communication bridge

Right click > The blueprint > Blueprint interface .

Create a new function in the blueprint interface If_Open.
At this time, the blueprint interface is set , You can close the blueprint interface window .

Open the interface in the blue diagram of the door ： Class settings —— Interface > Add the function just now If_Open

Two 、 Gate logic

1. Press the key to open the door

Open the door blueprint .
add to IF open event , And The opening event is connected .

Now the effect is that players press F Open door , The rear door automatically closes after entering .
If all have to be closed by pressing the key , Record the state of the door , Determine the switch according to the state .

2. Player blueprint settings

Open the player blueprint .

Right click to add F event

F Events are directly connected IF_open Interface , At this time, the direct compilation reports an error , We must give a goal .

3. Player collision detection

Use player capsule for collision detection , For collision Actor Traversal , If there is a door , Then directly execute the door opening event .

Click the capsule component —— Add components to start overlapping events 、 Component end overlap event
Add an array variable to store collisions Actor Information ：

• When overlap starts —— Add information
• At the end of the overlap —— Delete the information

When dragging components to overlap “other Actor” The pin is promoted to variable .

Change the variable type to array , Change of name , Delete —— Hold down ctrl Drag variables from the left to the blueprint , Create this variable key .

Drag to open the door Actor Key and create a new ADD“ Add to array ” function —— When components begin to overlap Other Actor Pin 、 The execution pin is connected to the function added to the array .
If the player collides with this object , Then put the Actor Add to the one that can open the door Actor Array .

Drag to open the door Actor Key and create a new Remove“ Remove from array ” function —— When the component ends overlapping Other Actor Pin 、 The execution pin is connected to the function added to the array .
If the player does not collide with this object , Then put the Actor From the one that can open the door Actor Remove from array .

Complete blueprint of collision detection .

4. Collision detection information traversal

At this time, we have the information of the collision object , Next, choose from the inside .

Create a new one that can open the door Actor key , Drag and create For Each Loop Traversal function ——F The event is connected to the traversal function execution pin —— Traversal function and If Open Connected to a
The complete logic is ： Press F—— Pair collision Actor Array traversal —— There is a door —— The door blueprint executes the opening event .
Why use arrays , It should be that players may encounter multiple at the same time Actor, Or before leaving the last Actor When they meet new Actor.