© 2015-2018 Xander Clauss

Building a Bigger Shooter:

The Grand-Scale Level Design of an MMOFPS

The Project

         I was brought over to the Planetside 2 team in October 2011, about six months into development, to work on various facets of design implementation. Though I filled a variety of roles in my 3+ years on the project, such as streaming, writing lore, and theming/naming weapons, the vast majority of my time on Planetside 2 was spent designing and building the environments where players would fight. It was an exciting part of the game to work on; the World team launched Planetside 2 with a stage set for the game's massive battles: three 8x8km continents, each with anywhere from 50 to 100 unique, handcrafted bases.

 

Given the game's complex moment-to-moment combat, experimental nature, and an almost unexplored genre, Planetside 2 proved to be a challenging title to initially make levels for. Looking at some of the high level features alone, such as the combined arms combat, player freedom, and its immense scale, we found what works in Planetside 2 is a bit different from the typical FPS.

The L-B-F Layers

         The scale of Planetside 2's combat splits the game's level design concepts into the three L-B-F (ləˈbʌf) layers. These range from the abstract, continent-wide Lattice down to the Facility, a man-made outpost where infantry fights occur most. Each individual Facility on a continent is far from self-contained; the composition of individual outposts can have a significant butterfly effect on the entire regions depending on how well it harmonizes with other the layers, and vice versa. This piece will focus on Quartz Ridge and Indar Excavation Site, a couple of bases on the western coast of Indar I had personally iterated on over several years. Though initially we tried to solve a seemingly neverending fight between the two bases, it became a testing ground to iterate and observe changes in player behavior.

          At the highest layer of PS2's level design is the Lattice; a zone-wide web that connects any given base to at least two more bases nearby. While the Lattice itself is an abstract layer that only provides the answer for "Can I attack this next base?", this zone-wide skeleton is where the continent gets its flow.

 

It can function like Indar, where asymmetry, high outpost density, and extra connections make enemy attacks difficult to predict. Or like Amerish, which uses a connection-light Lattice, pushing players to commit to a single lane and giving junction outposts a higher strategic value.

 

We also noticed an important facet of players' satisfaction and natural integration of the Lattice was the interplay between connections and the terrain around them. Being able to see a base as 'attackable' only to find out it wasn't proved frustrating, and helped shape the look of our later continents.

The Lattice around Quartz Ridge and Indar Excavation, the area we'll be taking an in-depth look at. In this picture, Quartz Ridge and Indar Comm Array are vulnerable to each other, and a fight may pop up between them.

          If the Lattice layer forms a continent's skeleton, the Battleground layer is its muscle. Forming the middle of PS2's level design and arguably much of the game's iconic feel, the Battleground is composed of the terrain between any two facilities. We agreed that the aesthetic of a massive, combined arms advance towards an outpost and the resulting fight were experiences that really defined something special about Planetside, so we did our best to encourage these ad-hoc field skirmishes.

 

We also discovered how the flow and rhythm of a Battleground is shaped by what's carved out of it via objects and geographical features. Open spaces encourage combined arms firing lines, where shots are exchanged from the extreme sides of a vast no man's land. Adding gentle, rolling hills and human-size cover gives infantry safe lines to follow along the field, leapfrogging between objects to break LOS of high threats. Cover or buildings large enough to deploy a mobile spawn truck behind act as repeaters, refreshing the flow of infantry that may have become 'attenuated' while crossing the field, and allowing that force to more easily push towards the next outpost.

 

The arrows show typical troop and vehicle movements moving along the Battleground between Quartz Ridge (left) and Indar Excavation Site(right). The long barren stretch of land and the Excavation Site's high vantage points makes the second half of this Battleground advance high in attrition.

          The final stop on this human body metaphor is at the lowest layer and heart of any fight, the Facility. At this layer, PS2's level design overlaps a considerable amount with modern military shooters. Here, a man-made Facility contains capture areas that transfer ownership when held by an attacking force for several minutes. When it finally changes hands, any connected bases are now vulnerable to attack, and that force can continue to move along the Lattice and gain more territory.

 

Looking at its most basic pieces, an individual outpost is created by choosing locations for several cap points, choosing roughly equidistant (50-150m) locations for hard and mobile spawns, and then partitioning out layers and lanes that can scale to accommodate anywhere from 20 to 200 players.

Arrows show a typical circulating fight at Quartz Ridge, a Facility, once the attackers have deployed mobile spawn points at the perimeter. The road on the bottom allows a force to deploy in multiple locations, putting pressure on the defenders and spreading them out, ultimately making the fortress a little less defensible.

While there's only a few basic pieces that  form the foundation of an outpost, there are a significant amount of variables to consider when making decisions due to the game's depth and unrestricted player behavior. At this level of granularity, some choices were made to restrict this freedom to provide consistent experiences and scale with varying populations. For instance, nearly all capture points are housed in a building or covered space, limiting the engagement range to the room it's in, as well as restricting cap point combat to infantry-only.

 

As a result, the base can function well both in small fights with only 20 soldiers, as well as with large, combined arms fights that bleed far out of the cap point area. While the ability to keep a point clear by placing snipers on a nearby hill or carpet bombing the it with gunships technically offers depth in number of options, we found Facility interiors played best when defined to mostly infantry at 5 to 50 meter engagements.

The History & Evolution of Planetside 2's Level Design

         By the time I had joined the team, the framework for Planetside 2's environments was forming but still very much in flux. Indar was on the 2nd of its 4 total revamps. The world team had decided to go with a different take on Facilities than Planetside 1's cloned underground labyrinths. Opting for a variety of freestanding buildings, partitions, platforms, and terrain props, the sequel's capturable levels were slated to be unique, handcrafted, and about half a dozen times more numerous. With only about a year left until launch, we needed to both learn what made a good Facility, and also bang one out about every 3 days.

The Lattice:

         The Lattice did not exist at the game's launch, requiring friendly territory to only touch the enemy for it to be contestable. Implementation of the Lattice was talked about before we had even launched beta, but it remained a contentious feature from Planetside 1 we held off on. Combined with the number of capturable outposts, many facets of the other layers suffered from the lack of structure: smaller fights, difficult to predict attacks, and even increased difficulty when making Facilities. More bases were vulnerable at any given time, and many bases were constructed to be attacked radially instead of linearly along the Lattice, bloating the time required to create solid levels due to the increased difficulty.

The addition of the Lattice system focused players into larger groups and moved them along more understandable routes

We opted to give Indar the Lattice treatment 4 months after launch in February 2013. Our choices when planning for the first Lattice included making connections based on what made sense visually, removing outposts that fit poorly with the lattice, limiting the amount of bases with 4+ lattice connections, and better balancing each third of the map. My role on this last Indar revamp was also to manually tie each hex to a Facility, as well as better align key elements of each base to fit onto the lattice. Adjusting about 80% of Indar's bases averaging 4 hours each and the data work for hexes, the revamp ended up taking approximately 300 hours over the course of five weeks.

 

The implementation of the first Lattice on Indar is by far the most flawed, but ultimately proved a success; the majority of players preferred the structure provided by the new feature, and many substandard Facilities were brought up to higher standards. We continued retrofitting older continents with the lattice over the next year, updating Esamir mid-2013 and Amerish in early 2014. Hossin, our latest continent, was designed with the Lattice from its conception, making it the most balanced at the highest layer of the game's level design.

Linear bases work best with <4 lattice connections, have a defined back end, and are quicker to implement. Radial bases are more difficult to put together, but perform much better at Lattice junctions where they're expected to be attacked from all sides.

The Battleground:

         Battlegrounds weren't a very developed concept at launch and weren't picked at until we looked at the space between Quartz Ridge and Indar Excavation site post-Lattice. We were seeing fights float between these two outposts for hours at a time without either of them making much progress. They both functioned properly, and fights would take place at the outposts and be fun, but capturing territory always seemed just out of reach. An empire would have their soldiers and vehicles advance to the other side, fight their way over, and upon respawn would find themselves back at their old base on defense all of a sudden. What was causing this fight to stagnate?

 

While the answer didn't lie totally with the World team's domain, the majority of it had to do with the negative space between the two Facilities, the implementation of the Lattice, and coincidence. With the Lattice being laid on top of Indar, the dynamics of some areas changed a little with the reduced connections between outposts. Quartz Ridge and Indar Excav are a good example of this, as the open area previously was more flexible in where you could attack from. After the Lattice, bypassing either of these two bases meant a long detour, so they now had strategic value as well. So not only has the region suddenly become a high-value chokepoint on the continent, the half-kilometer of land between the bases coincidentally happened to be flat and barren.

 

Pre-Lattice, these bases could just attack everything that was next to them, and those bases could also fight whatever was next to them, so large forces rarely carved any sort of discernible path through the map. The Adjacency system led to more of a creeping, shapeless blob that grew and supported lots of smaller fights, and often one large fight that could be sieged indefinitely, a dynamic caused by difficulty in keeping player populations together.

 

So why did the fights stall? Originally, Facilities could expect attackers from 4-6 different directions and the pre-existing terrain had generally worked fine. If it didn't, going around a tough base was much easier. After the Lattice, blobs happened far less as a result of the new skeleton, and forces moved in more predictable ways while still being offered strategic choices at junctions. This led to some growing pains in cases like the segment between these two bases, as the empty space here was now all of a sudden a problem: the bone had no muscle.

Lack of cover on an early 2013 version of the battlefield (left) caused players to execute lots of failed attacks from bad locations. The current version (right) shows their tendency to gravitate around cover, as well as how additional sunderer locations mid-way allow for increased attack success.

Our biggest change to this Battleground were the coral smokers and large building intended to cover a mobile spawn point, regardless of which base you were attacking from. We also added some small rocks outside of both Facilities, which infantry then stuck alongside both it and the larger cover, changing their previous out-of-the-way behavior now that better options are available. Additional mobile spawn spots are available along the length of the Battleground as well, creating layers and redundancy when destroyed; the next spawn is more likely to be <200m away instead of >400m.

 

It was a great test ground to iterate on and see how the fight played out after the changes went live. We knew that the bases were fun, shared the same lattice, were on the edge of the map, and that it was a blank slate; our changes were totally additive. With the knowledge of how the fight functioned with nothing on it, we could directly observe changes in player behavior. Ultimately, less cover means longer Battleground fights and more killing fields, and adding more cover pushes the fight closer towards the Facilities.

 

As we found out how to build better Facilities, we learned that vehicles needed to be somewhat restricted inside them, so these open field fights provided much of the combined arms fights. The march across an open field with your empire and the subsequent clashes formed an iconic, immersive experience that was distinctly Planetside.

The Facility:

         The Facility layer is by far Planetside 2's most visible, concrete aspect of the game's level design, and the one that got fleshed out first. A facility consists of a capturable man-made settlement and the area immediately around it. PS2 was notable for having dozens upon dozens of these on a continent, each one handcrafted (save for the major facilities and construction sites) and themed to fit the game's sci-fi post-Earth world. 

 

Making Facilities for Planetside 2 proved to be difficult early on, and we found ourselves revising our work often as we learned to craft better fights. As mentioned before, the game's unique features often meant unknown results when put into action, and the game's scale meant testing how something played often required a live player population.

 

Scale: With the Lattice being put into place, many pre-existing Facilities became obsolete design-wise, as they were too small to contain the now-commonplace larger fights. As a result, it was important to build bases to scale to larger populations while still allowing small skirmishes. We accomplished this with multiple layers that create additional lanes when the population gets high, as well as having facilities have a larger minimum size.

 

Quartz Ridge at launch (left) compared to the latest iteration (right). SInce this Facility became an important chokepoint with the introduction of the Lattice, increasing its footprint and playable space allows it to accomodate the large fights it attracts.

Combined Arms: Early on we wanted to extend the combined arms aspect to most of the Facility as well. It didn't mesh well in many cases, often leading to infantry getting trapped and shelled inside the spawn room. Towers are an exception to this rule, but most outposts are now restricted to infantry only. Vehicles found their roles in siege combat, taking place right outside of a Facility, and in the Battleground, where they are their most powerful.

 

Hard Spawns: Spawn rooms are how the owners of a Facility come back to life if they're killed nearby; they're shielded and provide a safe place to take a second, get your equipment and push out. Many of our early bases suffered from spawn camping problems where the attackers would surround this saferoom (from a distance) and wait for players to exit. Since it was predictable where they were going to come out of, fights got one-sided once they reached a certain point of the capture process, or if the defenders were outnumbered. We mitigated this by using larger spawn rooms with better vantage points, DoT areas around spawn rooms for camping attackers, shielded teleporter rooms to warp defenders across the base, and multiple cap points to spread out attackers.

 

Playstyles: Planetside 2 gave players a lot of options for abilities and weapons, and this variety of choices bled into the level design as well. Placing a hackable equipment terminal for Infiltrators to access suddenly lets everyone switch to counter nearby threats. Placing a fence or wall to block an alley acknowledges that you want most players to have to go around, but don't mind Light Assault flying over it as a shortcut. Ramparts on walls often establish a symbiotic Medic/Engineer/MAX vehicle-repelling ecosystem to repel sieges.

 

Performance: Though high frame rates were always a game-wide goal, guidelines to ensure solid performance affected the way bases were built. Our hand-built outposts opted to use a collection of buildings, props and construction materials (platforms and blocks) with the idea of taking advantage of hardware instancing, favoring a few common props over of a ton of unique ones. During continent-wide performance passes, culling out excess objects, adding occlusion and pulling excessive terrain textures were part of getting more out of the hardware without visually impacting the game.

Terrain: The open world nature of the game lead to some unexpected problems regarding vehicles, terrain, and how they interacted with a Facility. Since player behavior is pretty unrestricted, a base that is perfectly fine in its own vacuum may have completely unexpected dynamics because of map features 150m+ away. A distant hill may be easy to access and become a popular spot to shell infantry in a 'secure' courtyard, or a tall mountain or canyon can make aircraft nearly impossible to knock out of the sky with ground-based AA. Here, we placed Facility-owned turrets for active defense, and used LOS blocking props like trees to passively bring vehicles in closer.

 

NPCs: Developer-placed NPCs were primarily related to base functionality: spawn rooms, capture points, etc. For performance reasons we never pushed this envelope too far; adding an extra NPC per outpost meant the server performance suffered. Vehicle and Equipment terminals, however, provided areas where they were present as high value for both defenders and attackers. Defenders can use equipment terminals it to change roles or resupply ammo, and attackers can hack it to gain some extra flexibility and a foothold when pushing into a base. For vehicle terminals, these can also be hacked by attackers to buy a mobile spawn point, deploy, and essentially start a fight.