The Penumbra - CitraLux Studios

Grade Awarded - 2:1

Introduction

The ‘Penumbra’ is a Virtual Reality stealth game, set in a fictional world based upon early 20th century noir movement, popularised by Hollywood in the 1940s/50s. The player plays as a Penumbra, an oppressed race, persecuted for their ability to exist in both light and dark within a world ruled by Lumens and shade (Races that exist solely in the light and the shadow respectively).
The objective is to escape imprisonment and navigate this dystopian environment uncovering the worlds shadowy past. Ultimately aiming to break the penumbra out of their servitude. To aid the player’s journey they must steal a highly experimental light manipulation device which can force either the Lumen or the Shade out of existence, thus enabling the player to safely traverse their hostile surroundings.

My Roles

• AI Programmer: This was my specialism in the project and where most amount of my efforts were focused. Created AI which patrolled and searched for the player.

Contributions

• Enemy AI: I created lumen and shade enemy variants, setup patrol paths and created a pursuit and search system
• NavMesh: Setup the navigation mesh in all levels to ensure the correct AI pathfinding
• Build Creation: I was in charge of creating weekly builds, this allowed us to get frequent playtesting
• Trailer Materials: I recorded gameplay footage, collected resources and materials for use in the trailer
• Enemy Light Interaction: Created the mechanic which determined whether enemies were in the light or dark. Altering their properties depending on their type (lumen/shade).
• Bugfixing: After playtesting sessions, all discovered bugs were allocated to me and the other programmers and swiftly fixed

Enemy AI

To create the AI, I decided to use behaviour trees for the project. This was for several reasons:

• Ease of troubleshooting due to its visual nature.
• Modularity allows nodes to be interchanged to quickly create or modify behaviours.
• Familiarity with this approach.

I used a package from the asset store to avoid having to create a behaviour tree system from scratch which would have taken precious time from the project see below

Find Player

I began by creating a node which would detect the player, so that only enemies close to the player would engage. I went with a 'field of view' cone approach, by checking collisions in sphere then checking if there is a valid angle to the player.

Interaction Mechanic

This mechanic was responsible for making the shades(beings of dark) disappear when they entered any light source, only reappearing once exiting the source. While doing the inverse for the lumen(beings of light), only when entering the light would the lumen become visible.
This enabled interesting gameplay options, with another mechanic the light device. This device allowed the player to move light sources in the level to other empty points.

Light Interaction

First I created two different tags, one for shades and the other for lumen(light). Then I set the enemies to a default state, since all enemies did not start in a light source. The shades were active by default, with the lumen being deactivated. Then once entering a light source, a collider would represent the area of that light.
Since the enemies were already in the correct state, all that was needed was to invert the boolean. Activating the lumen, while deactivating the shade. The same function would be called once the enemies left the light source.