Holowood was a top down concept that came from the retrofuturism theme of Knockout City. Instead of simply watching films on a screen, they would be holographically generated at a drive in theater for audiences to enjoy. The idea to do this was to have holographically generated geometry rise from the ground, stay for a period of time, and then puff out of existence before repeating. Each of the Scenes would need to be radically different from the others to promote gameplay variety and to make them memorable.
The very first attempt at this was done in UE4, using the blueprint scripting system to cause a different level file to rise after a set period of time, delete itself and then trigger another level file to rise after that. This took me some time to figure out (mostly the storing of the different level files in a list and then choosing one at random) but once it started rolling, it really opened up the level for layout exploration.
The initial few layouts stuck to what worked in Knockout City in the past: fairly natural transitions from low to high ground, a variety of structures and pathways around the map, and at the center of it all the Holographic grid. However, what this approach failed at was creating enough incentive to fight in and on the central Holographic arena. Players would spend more time on the exterior of the map than in the middle. Additionally, the map at the time was asymmetrical, which meant the art team would need to individually theme various areas around the map, and lose time because they couldn't replicate the work they were doing.
The approach we settled on was a symmetrical layout that emphasized the center of the map by making it the highest point. Additionally, the Scene's themselves would add additional height to the arena, which would draw players to it fairly reliably. The exterior of the map still drew players, but mostly as spawn points or locations to get balls or to escape from enemy players.
Holowood, because of this style of development, does have a pretty significant drawback. The overall space the map takes up makes it one of the smallest maps in Knockout City, and this can lead to players feeling trapped when they spawn in. Enemy players can very quickly rotate to the enemies spawn, and start the fight all over again. This would be very hard to change with the finished map, but a revised version would probably include a larger exterior or some additional way to mitigate the spawning issue (hovering spawn points at the edge of the level?).
The entire environment art team at the time worked on this map (Brennan Howell, Tristan Meere, Cory Hamilton, Michael Andrews, Erik McKenney and Steve Bucholz).