Zelda-s-target-locking-system

This project is an object locking system made with unreal for a course during my bachelor 3.

Sommaire :

• Presentation of the project.
• Game keys to use the mechanics.
• How to install the project.
• The different features of the project.
• Organization and structure of the code.

Presentation of the project :

The goal of this project is to implement a camera lock mechanic on Actors in Unreal Engine 5 using the Blueprint. By pressing the E key, the camera will lock onto the center-most Actor on the screen and the player will enter a custom movement mode. The player can then move away from and towards the Actor with the front and back keys, as well as turn around with the left and right keys.

This project requires a version of Unreal greater than or equal to Unreal 5.1

Game keys to use the mechanics :

• Movements:

  • Move forward / Get closer to the target : Z
  • Go left / Go left of target: Q
  • Move downward / Move away from the target: S
  • Go right / Go to the right of the target: **D D
  • Jump: Space

• Lock: Maintain E.

How to install the project :

You can download the latest version of the project here.

• or you can clone the git repository with the following command :

[email protected]:LeoSery/Zelda-s-target-locking-system--UnrealEngine5-2023.git

ou

https://github.com/LeoSery/Zelda-s-target-locking-system--UnrealEngine5-2023.git

If you have the right version of Unreal engine, you just have to open the file named: TemplateCameraLock.uproject.

The different features of the project :

In this project you have 2 possible movement modes, the Walking mode and the TargetMode.

Walking

This is the default movement mode of the project, you can move around using the keys explained above, and you can move the camera with your mouse like in an FPS game.

TargetMode

TargetMode allows to lock a target, to follow it with the camera and to move according to it.

In order for an object to be targeted, it must have the LockableObject component. The component can be found in: All>Content>FirstPerson>Blueprints. You can add this component to the BP of the actor you want to lock.

You can configure the key to lock an actor in-game by modifying the InputAction named "IAFocusTarget" which is located in the file "IMCDefault" which is located here: All>Content>FirstPerson>Input.

Once in game, when you press the button assigned to TargetMode, it will automatically find the target closest to the center of your screen and place the camera towards that actor. If your actor is moving then the camera will start following him. In this mode your movements are based on your target and you no longer have control over your camera which will start to stare at the target.

If a target is no longer visible to the player, after X seconds, you will lose the tracking of the actor and automatically return to "Walking" mode. The duration before losing the targeting can be adjusted by modifying the variable named "MaxTimeTargetCanBeInvisible" in the EventGraph. By default the time is set to 3 seconds.

If you lock an actor and it disappears from the world you lose the targeting on the object, and conversely if an object is instantiated and it has the component, it can become lockable at any time.

Organization and structure of the code :

The locking mechanism is organized in 4 main systems:

• The "LockableObject" component which allows to make an actor lockable.
• The search for the target actor.
• The tracking of the target actor by the camera
• The movement of the player in relation to the target actor.

The "LockableObject" component

Here is how the component works:

When the game is launched, the componenet will assign a Tag to the object on which it is present.

To add the component to an Actor, you can simply add it to an actor.

The search for a target actor

When you press the button assigned to the TargetMode, it will retrieve all actors that have the tag assigned by the LockableObject component.

Then, among all the actors retrieved, the function will define which actor will become the target by looking at the one closest to the center of the screen.

The tracking of the target actor by the camera

Once an actor has been set as a target, the camera will look at the target, if you move or if your target moves, the camera will continue to follow the actor set as target.

If the target passes behind an obstacle, the system will continue to follow it during the time configured in the variable named "MaxTimeTargetCanBeInvisible", after this time, you will lose the targeting and return to the "Walking" mode.

The movement of the player in relation to the target actor

When you have a target that has been defined, the moves are not calculated relative to the world but relative to the target.

If you press the key corresponding to Forward and Backward, it will move you closer to the target or further away from it.

The right and left keys will make you turn in a circle around the target. For this the system calculates where it should be around the target using the function "TargetPositionCalculation".

Then it moves to the calculated location.

More details on the different steps and calculations are given directly in the commentary of the Blueprints.