Prototype sampler # 1

So, finally, I’ve completed my last major developmental milestone and I think that deserves a post. 🙂

The above video simply shows the playthrough of some of the game mechanics. The quest has not been fully written yet, and though all of the game mechanics are working, they’re not readily apparent without some introductions. The video is mainly to see how adventure and combat are blending as one piece.

I’ve slaved away on numerous aspects to accomplish all the major milestones I had set out to do. There were a few additions to these, but they were minor changes, and all in part of the iterative process of figuring out the closest gameplay mechanics I wanted to implement in Unity.

Though my work isn’t done yet — there are still UI issues I need to sort out — and there are still some niggling bugs present in the prototype, it is largely playable. By ‘playable’ that means you can run around, talk to people, and shoot Robots, and get shot back. You can plant a bomb, blow it up, and you can blow yourself up in the process as well. You can ‘pox’ a powerlet to get energy, you can buy and use meds to heal yourself. Frankly, a few months ago I didn’t think I could end up saying all this in one paragraph.

Most of the joy, and fear, of this prototype has been the implementation of a bespoke AI graph framework. It’s a joy because it actually works; it’s a fear because it sometimes feels too deep for me to always grasp its innards when some things don’t go right.

I’ve gone through mounds of halved/quarter-A4 to-do sheets with heaps of orange highlighter marks signifying all the big and small tasks or goals I needed done. There are so many disparate systems working that that if I didn’t have a calendar tracking my progress, I wouldn’t be able to grasp what I myself had accomplished.

For example, here’s a quick run-down of the aspects.

  • Asset creation.
    • I’ve heavily used Janus to break out animated sequences.  Using FORFILEs, a Janus looping construct that iterates through the lines of a file, creating an animated character, such as the Player character, was simple as I needed only to set up one angle and let Janus break out all the other 15 directions. Variable frame ranges for a particular animation were also taken care of using the same principle.
    • Janus was an important cog in the making of the prototype because of the amount of iterations for the scenes. An element would sometimes become designated as an interactable element, which had to be split from the main scene and rendered separately.
    • NPC/Robot portraits had a separate animation and render, and specifically had to go through post-processing.
  • Tiled was used in making the maps, and Rex’s TMX Importer was used to carry that information in C2. I had to do some modifications to the TMX Importer to enable the retrieval of the Tiles and Objects image source. Tiled enabled me to experiment and implement concepts by introducing certain datatypes for the engine’s use, which informs me of how I may implement the maps in Unity.
    • This had to be balanced with Game Data Documents which are comprised of text-based files of varying structures. These Data Documents are the immutable attributes used by the systems. In the beginning, the data would come from different sources; one would be defined in the TMX, while others defined in a CSV table. As I progressed, I refined the categorisation of data.
  • The in-game Inventory system was one hell of an undertaking, The Inventory system is connected to the Trade system, which is further split into two variants: the Container system, and the Merchant system; the former simulates the ability to store items in ‘containers’, and the latter simulates buy/sell transactions with NPCs. Merchant data, like price, buy/sell limitations, and price adjusters are tied to tables and the NPC entity as defined in the TMX.
  • While the code related to the movement was entirely specific to C2, I had to nevertheless overcome these issues to get a working prototype. Pathfinding needed some optimisations, behaviours related to physicality of entities needed to be coded in relation to the established movement behaviours. This aspect will largely be replaced by Unity’s navmesh, in addition to a target grid overlay that I may custom-build myself.
  • The Action Strip (a.k.a. Astrip) system — the method for interacting with elements in the game — was developed to be authored using text files (like most systems in the game).It serves as the hub for all ‘adventure’ interactions. It was also designed to be generic so that the display of interaction results can be be tweaked directly from the text file. For example, a ‘look’ action,  at an object may initiate a display of a description, or the narrative box, or initiate a dialogue, or anything else that has been allowed in the engine.
  • The Convo system was another early development. Some additional Python code was necessary to convert the authored .graphml files (using yEd) into a Markdown format (for readability in a text editor). However, the development of the AI graph framework proved that the Convo system was inferior, though both used node graphs. Although the Convo system has not yet been upgraded to use the same (or similar) framework of AI, this would eventually be done when the port to Unity is made.
    • The Convo system could be called by the Astrip system.
    • The Convo system also allows implicit trade of items. For example, if through speaking with an NPC, it gives you an item to be used. The Convo system communicates to the Inventory system and places the item in the Players inventory.
  • The AI system used the TGF format to represent a nodal graph. Then an in-game parser and callback/event handler framework handled the execution of the AI graph on a per-Robot basis.
    • The AI system is connected to other systems, such as the Inventory, the Trade, Convo (dialogue system) and of course, NPCs/Robots themselves.
    • Using the AI system, a Robot can accost you to do a contraband check, which was one of the first implementations of the AI (even before combat).
    • The AI can contextualise its own dialogue with the Player, changing it from a contraband check to an arrest, for example.
  • Lookups for gameplay values, such as hit-chance, effect of skills on gameplay, were done using a non-linear interpolation that was accomplished by using Open Office Calc’s cell formulas. This allowed me to tweak lookup values utilising functions as opposed to doing it individually, per cell! This application was conveniently placed to export to CSV directly, so no other intermediate process was needed to get it to C2.
  • The Combat system is closely tied with the AI and is comprised of many factors, a few of which include:
    • Alert level behaviour of Robots; certain actions at a certain alert level means differently for Robots. For example, running or crouching is OK when Alert Level is 0. But when the Alert Level is 1, running or crouching is interpreted as suspicious and Player will be fired upon.
    • Behaviour of Robots differ from one another. Some guard, some patrol, some check for contraband.
    • Offensive component
      • Player accuracy skill
      • Weapon attributes such as range, max_range, weapon dropoff (weapon damage and chance to hit is affected)
      • Rate of fire
      • Dual-wielding of weapons
      • Crouching increases accuracy
      • Bomb placement and detonation
      • Shock effect; certain weapon may stun a Robot for a period of time.
      • GMAC system, which is a modifier on top of a typical random number generator.
    • Defensive component
      • Use of cover for defence
      • Crouching reduces profile, increases Player defence against being hit
      • Running increases Player defence against hit but only if running perpendicular to Robot.
    • Stealth component
      • Crouching behind low obstacles for stealth
      • Noise level when running; Robot hears you!
      • Glitters is Electronic Counter-Measures and makes the Player invisible for a short period of time.
    • Hacking powerlets to get more energy, and the associated success rates, and the penalties for failure
    • And others that are too lengthy to include, but you get the idea…

Normally, a prototype is small, whose gameplay represents the root of what the game is about. Sometimes, a prototype is created to determine if a gameplay works or not, or if people like it enough.

But I built the prototype as a technical reconnoitre  of what I’m going to come up against. You can say I was also trying to form a beachhead at the same time. I don’t know if people would like it, but I can’t be dissuaded either way; I’ve gone this far solely on the excitement of taking a childhood game to my present.

But a prototype is also made to present the gameplay as clear as possible, that if the prototype is fun to play, then the real thing would be as fun, if not more fun to play. The problem I have with Citizen is that it is an adventure as much as it is a shoot-em-up game. The fun in 2400 AD, Fallout, or Shadowrun, for example, is the fact that it is an adventure. But I find it difficult to express the full adventure by doing a half-adventure. I think that’s due to my lack of experience writing for games. At the same time, I think that I’ve been focused so much on the technical aspects that I’ve not really dug as deep as I should into the potential of the narrative. I’ve been working on the framework in which I hope to base an adventure story (of which I have a first draft already), and I think that this prototype, as it stands, should be just seen as the prototype for the framework.

More to come.