Life Derived From Art Derived From Life

Sometimes the models tell the story and you’re the one putting it together.

While working on one of the latest campaign level planets for Solar Purge, I was hit with a recurring writing dilemma: how to build an ecology out of the disparate enemies on the planet.

Previous campaign levels had been a lot easier to work out – in the first half of the Lockjaw Prison tutorial section we’ve kept enemies to a single type (robotic) both for plot reasons (it’s introduced to the player right away as being heavily mechanized) and to assist in game play (enemy types can be affected by weapon perks, so this allows us to introduce specifically anti-bot and anti-alien perked weapons to show players the difference).

On Titus, the entire level & enemy models/AI were more or less complete when I joined the team. (I did end up adding a mini-boss and a few new objectives to give players a sense of taming the planet as they crisscross the map, but that’s a story for another post.) The biggest challenge there was creating an ecosystem out of models which were already in-game. Since the entire level is designed to have a very Starship Troopers (TriStar 1997) feel to it and the boss was already explicitly the queen of a hive it was relatively simple (after a few dozen hours of research) to put together a species of eusocial arthropods with the ability to communicate via stochastic resonance.

But the second planet was a bit tougher due to the much larger scope. The players initially arrive in an overgrown and abandoned colony, discover a few survivors, then venture into the dense alien swampland and pass through a forest clearing before finally coming across the ruins of an ancient city.

Like on Titus, the enemy library was already in place; unlike Titus, I had actually been around to help guide which assets we incorporated into the enemies and foliage. Most of the enemies were easy to place in either the wet marshes or the dry(er) open grassland and ruins, with a few able to work in both areas making for some solid gameplay variation.

But one enemy confounded me – “BP_Jellyfish.”

It had been in the game since before I arrived on the scene, and it was easy to see why the enemy was imported into the project as “jellyfish,” but what did jellyfish have to do with a forest? Or ruins? I briefly flashed back to my very early childhood, playing Slymoids (Texas Instruments 1984) on my TI-99/4A. If they could find a way to invade a cowboy’s castle, they could find a way to live in our alien forest!

Just not as a jellyfish.

During early design meetings for the level I had brought up the idea of cordyceps fungus – a rot spreading out of the center of the swamps to mix up the encounters and keep tension high in a part of the level where we give a lot of agency to the player to explore on their own. Additionally this would justify why the denizens of the swamps and forests would be working together against the player rather than trying to eat one another! The idea was well-received, and we agreed to re-frame the damage radius around the enemy as a spore cloud which could injure the player and heal enemies. The enemy itself was rechristened “medastia.” Still, I struggled to find a way to tie all of this together in gameplay.

My big inspiration came when looking at some newly acquired assets that had just been imported. One of them, ToxicPlant, had a series of stalks growing off of it with small bulbs on the end. It reminded me of something…

It was a real eureka moment!

The “tail” of the medastia would now be the stalk of the new “plant,” which itself would be a sporangium for the enemies themselves! It would be easy to add the same damage/healing radius to the sporangia, but there was still a small problem: how to get these brightly colored materials to stop clashing with the more muted and natural colors in the forest.

The answer to that came in repurposing one of our existing art assets! We use a large pack of moss pile assets to create the overgrown look throughout both the new colonial ruins and the ancient forgotten city, and their material details already had a “Diffuse Detail Color” checkbox…

One duplicated material instance and a few color corrections later I was able to turn a “MossyPile” into a “MoldyPile,” and went to work in the editor.

Each sporangium in the level is now surrounded by purple mold meshes, themselves connected by long rows of distorted mold meshes to create a look which helps us lean into the color contrast – the medastia infestation now feels separate from the forest’s natural ecosystem but explains its own life-cycle to the player visually: they encounter medastia enemies near the sporangia and can see how the sporangia are physically connected to one another, with new tendrils spreading out from each “node” in the group.

There is even a welcome side-effect, in that the connected sporangia signpost the player through the swamp and into the next part of the level!

Once again, it’s about finding ways to iterate on what’s there to help everything gel together!