Since leaving The BRIT School, I've mostly been focused on studying the technical side of creating games in Unreal Engine. This page shows some systems I've created while doing so. Please note that as all of this is tech focused it doesn't have any pretty visuals to go with it.
StateTreeCameraDemo.mp4A fully data-driven camera system utilising Unreal's State Tree plugin and experimental Gameplay Cameras plugin. The demo video on the left shows the state tree being used to select a camera (right) and the Rewind Debugger showing the state tree over time. (bottom)
There is a defined "change camera" input. The player can swap the shoulder the camera looks over by tapping it, (change position) and they can swap between First and Third person perspectives by holding it (change perspective).Â
When one of these inputs is received, the character checks what their current camera settings are and chooses an appropriate one to swap to accordingly. It then sends a message (delegate) which is received by the Camera Director, a concept of the Gameplay Cameras plugin. My camera director then sends an event to the state tree with all the relevant info attached, where a state is chosen and an "Activate Camera Rig" task is ran. Camera modes are cheaply communicated via Gameplay Tags.
This method of creating a camera system is highly extensible, and it is easy to add new camera modes.
My implementation also supports networking (multiplayer), with the system ensuring that one player making a change to their camera will not affect others. Being in first person also causes the player's character to face the direction of their camera, which must also be explicitly replicated.
GameplayFeaturePluginDemo.mp4Game Feature Plugins are Epic Games' solution to adding content to games in a modular and dependency-free manner. It's how they do their seasons and limited time events in Fortnite.
The demo video on the left shows a base game running, and then I activate a Game Feature Plugin I created which adds health and stamina to the player, as well as the ability to dash (which consumes stamina) and spawn areas which heal or harm the player's health. All of these features are implemented using Unreal's Gameplay Ability System (GAS) Framework.
Game Feature Plugins are a good way to add new features to a game because, due to the way they are implemented, it is entirely impossible for the game to know anything about the plugin's content. This is helpful because it forces you to design in a way such that all aspects of the game work independently and do not end up linked together in a problematic manner where disabling one part of the game breaks another part.
GAS Is a framework designed to handle typical video game things like abilities, stats and status effects. My Game Feature uses this framework extensively. The three main concepts in GAS are Gameplay Abilities, Effects and Cues. Abilities are things characters do, like dashing or attacking. Effects modify stats, like health. Cues are visual or audio effects. A gameplay ability can apply effects and cues to other actors, for example an attack ability may apply a damage effect and trigger a blood cue. Effects and cues can also be applied outside of abilities.
By default, GAS only allows gameplay cues to be stored in the main game content folder. I, however, wanted to store a feature's cues in that feature's plugin's content folder. This is not bad practice, it is done in official Epic projects including Lyra and Fortnite. Unfortunately, there is no built-in solution to allow this, as the Gameplay Cue Manager (GCM) only searches in the game content folder. I looked at Lyra's code and found that they have implemented a custom GCM class which searches for a custom type of Gameplay Feature Action called "Add Gameplay Cue Path". As I wanted this functionality in my project, I implemented this myself too.
