Entropy

A problem we had in Entropy was a lack of situational awareness because of how dark the game is, and we didn't want to increase the brightness as that would ruin the immersion and feel we wanted. The idea I came up with was having thousands of glowing insects crawling on the walls, floors and ceilings of the levels. We didn't want them to constantly glow so we settled for having them absorb the light you, as the player would emit from the light gun. Having them behave like old light switches that would glow in the dark meant that we could keep our environment dark and use emissive materials on the insects to help the player orient themselves.

Because we wanted them to interact with the light orbs the player would shoot, I originally designed the system using Blueprints but quickly switched to using Niagara, Unreal Engine's particle system. This was because it would be highly inefficient to update potentially tens of thousands of insects on the CPU. The insects use signed distance fields to traverse on meshes in the world and walk around pretty mindlessly using various forces.

Implementing interactivity with code was a daunting task that actually proved to be quite easy using Blueprints. I also struggled a bit with creating custom scratch modules that allowed me to significantly simplify the particle update state by hiding complicated code beneath easily understandable function names. With all of this I managed to make the insects flee from the player as well as the impact of the light orbs. Making them glow temporarily after being exposed to light was achieved through the use of a custom scratch module that updates the particle color in the material the insects use.

This was a whole adventure into interactive visual systems and learning Niagara, which I really turned out to enjoy using! What I found coolest was how easy it was to change variables from code as well as it being possible to call a Blueprint function from the VFX system itself!