Going Vertical with the Design

Based on a trip to Malta, I fell in love with the old, tight streets, colorful buildings and oriel windows, and the beautiful seaside! I felt that a narrow, hilly environment would make for an interesting environment that also catered to the typical design philosophy of "corridor-shooters". As such, I designed a linear journey that takes the player up and down the town's streets and through residential inlets.

As I wanted to use Half-Life 2's combat elements, I designed the level using Valve's Hammer Editor and Source SDK. Going into this project, I was aware of one caveat: the Source engine, at its core, is tailored toward enclosed spaces like hallways. The open, vertical nature of my level design meant I would need to keep heavy optimization in mind as I built the map.

Many steps were taken to optimize the map. I split the map into 2 sub-maps that the player seamlessly transitions to, just like Valve did for the Half-Life games.I ensured that any surface that wasn't viewable by the player wasn't assigned a texture (denoted by the bright yellow "NODRAW" texture in-editor). There were many areas where I had to manually dictate where visibility areas should be cut or clumped together by the map compiler, optimizing both the compilation process and runtime rendering!Lastly, I learned that Source handles the rendering of static models more effectively than brush geometry, so I converted many larger brushworks into models to help lessen the engine's burden.While time-consuming, I felt it was very rewarding to heavily optimize the map, as I didn't need to sacrifice much of my initial vision of the level, both gameplay- and art-wise!

Guiding and Enticing Players with Scripted Sequences

I wanted to employ multiple scripted sequences throughout the map to not only guide players, but make the environment feel dynamic and lived in as well. With Hammer Editor, I used the same entities and general pipeline that Valve would've utilized when developing Half-Life 2 and any Source game that followed.

I introduced Half-Life 2's staple enemy, the Combine Civil Protection, by setting up a sequence where the player witnesses a Combine officer attacking a citizen and pointing to the player, insinuating that they're next and should get ready for combat.After acquiring the pistol, a zombie smashes through a nearby door, intended to startle the player and supply them with the first target of their new weapon.

I sprinkled set pieces throughout the level to lead the player to new areas and provide some additional excitement.
By activating a radio signal and returning to a nearby area, a previously inactive vehicle revs up and smashes through a gate before exploding! This event opens up a new passage for the player and alerts them in a bombastic way.As the player proceeds through the map, they will be ambushed by enemy groups or witness enemies fighting each other. These events help make combat feel less static and predictable while also fleshing out the world by sticking to conventions established in Half-Life 2. Zombies are mindless, hostile beasts that threaten both the player and the alien Combine, so it's only natural the Combine would retaliate toward the zombies as well.

Working With Limitation and Aesthetic

The major requirement for this mapping project was to design an area within 1280x1280x256 units of space. Secondly, the area had to be accessible from a template hallway provided by the organizer, as a means of adhering to the tower theming.Due to the abundance of industrial props and textures in Half-Life 2 and the moderate amount of space available, I decided to design my level around a warehouse aesthetic. This aesthetic choice influenced what challenges I would include, and how they were presented.I also took influence from the surreal nature of the project's core theme: a bunch of disparate rooms assembled on top of one another within a tower. Since the project's concept isn't grounded in reality, I decided my challenges didn't need reasonable justification for being where they were either! This meant I could have laser beams, moving platforms, and exploding barrels without worrying about compromising the atmosphere of the project.

Going From Plan to Final Build

Once I had my industrial theme established, I started a paper sketch of the level before finalizing the design in Adobe Illustrator. When planning and looking over the size restrictions for the map, I felt that focusing on bite-sized movement challenges over combat would allow me to make good use of all three dimensions of the provided area.Stepping away from combat also meant I could experiment with concepts I haven't attempted before in Source, such as timing challenges and death traps. Being based on Half-Life 2, I did include some combat in the form of reflex challenges! Players are pitted against a few headcrabs throughout the level to break up the platforming gameplay, and two zombies serve as the final challenge!

To the left, you can see an early greybox of the starting area. At this point in development, I had some of the challenges implemented in a testable form, such as the Barnacle maneuver challenge (where the hanging creatures are, near the upper left corner of the image).Among the sea of orange and grey dev textures, I was getting a feel for the general texture usage of the map as well. Based on the picture below, I definitely found a set of textures I was satisfied with for the starting area at this point!

Here is what the starting area looks like in the final iteration of the level. I added plenty of prop models and trim textures to really sell the warehouse aesthetic. Yellow light sources are accompanied by glow sprites and old fluorescent tube props to reinforce the aesthetic further (and provide the player with light, of course).The lighting in particular took a lot of minor movements and map compiles to get just right, but I was able to afford the time thanks to the relatively small scale of the map, and I enjoyed doing it!

Using the Level Editor

Using the level editor J.A.C.K. (which is meant to mimic and enhance the features of Valve's Hammer Editor), I manipulate primitive shapes, known as brushes, to create the level geometry. Using mainly cubes, arches, and cylinders, I can create spiral staircases, pillars, giant door mechanisms, and more.Because the environments are based on the Eldritch settings of Quake, I can take liberties on realism and instead focus on eye-catching and alien set pieces.

I love creating outdoor areas! Since Half-Life doesn't have dedicated support for terrain as many modern engines do, it's up to me to manipulate the brushwork to make interesting landscapes.By splitting brushes into triangular shapes, I can then manipulate their vertices to simulate cliffs, river banks, and more! It can be a time-consuming process, but it's always rewarding in the end.

Entities add interactivity to the world: enemies, doors, lights, and much more. Some of the stand-out uses of entities I took advantage of include creating scripted sequences, populating the world with items and enemies, and creating interesting lighting.Using a community-modified version of Valve's Half-Life SDK, I created my own weapons and enemies. I was able to define my new entities in a file that the level editor parses, allowing me to place them like any other entity in my maps.

Creating an Open-Concept Space

I'm a big fan of circular level design; when you make the player start in one area and have them return to it later, the areas you explore feel more alive and important. The player wants to open a door, but they can't yet, so they naturally look elsewhere for the key.Ultimately, the journey is still very much linear, but by having light backtracking and overlapping areas, the player doesn't feel like they're just following a straight line.

I applied the same philosophy to side paths as well. Backtracking with nothing new to experience can feel like a waste of time, so providing an exit back to an existing area makes the player feel like they're still progressing forward. The player also shouldn't feel like they've missed out on content on the main path since they're back to somewhere they've already been.Based on my own experience playing games, I love providing players with the same "eureka moment" I feel when I'm led back to a previously explored area!

Creating AI That Can Move Like a Player

As part of the AI development team, my primary task was implementing movement behaviour for the virtual fighters. To make navigation efficient for the AI, I created a node-based pathing system. By placing a few nodes on a given stage, the AI can decide ideal paths and navigate to target players.

Nodes are very flexible, with many variables accessible to the developer, such as the distance at which AI players will consider jumping to the node, or whether the node will be moving with a platform or not. I implemented some Unity Editor functions to help expedite the implementation process, allowing me to automatically link nodes and populate the node graph, detect and pair any moving platforms with a node, and more, at the click of a button!

I implemented a Finite State Machine to handle movement behaviour. The AI can chase along a path, directly approach, jump towards a target, etc. With a state machine, distinct behaviours and connections between other states could be clearly defined. Additionally, I simulated holding down and letting go of the jump input in code to ensure that jumping didn't feel static for the AI, but more human instead.

Lights, Camera, ACTION!

To smoothly track up to 4 players, I implemented Unity's Cinemachine system. I fine-tuned camera variables such as movement speed and damping, dead zones, and zoom, until a satisfying balance between playability and look-ahead was achieved, dictated by both developer and player testing.

I used Cinemachine to enhance play in many other ways as well. With a line of code, my camera controller can be told to zoom out to give players a full view of the stage. This functionality is used when mini-games or stage hazards appear on screen, grabbing the players' attention and allowing them to always track whatever event is currently happening.

I also implemented screen shake to specific attacks and events to make actions even more satisfying. Whether it's landing that last hit from a combo or a giant laser beam firing off in the middle of the stage, screen shake helped sell the weight of many different actions!