Tag Archives: Mert Börü

3-bit Node Graph Architecture for Next-Gen Game Development

Speaking of my latest video game development project, yet an another milestone achieved. – Quite a tough one, indeed!

But first, please allow me to focus on some of the very basic mathematical logic definitions heavily used in software engineering, so that we can clearly understand what’s going on under the hood of a decent game development process.

Don’t worry, it’s not rocket science 😉

Some theory

All video games have gameplay mechanics based on logic. A game is “a set of story driven goals to achieve” from a programmer’s perspective.

When you open a chest, solve a puzzle or kill an enemy, you are actually triggering a logic unit that is predefined within the game code. Depending on game’s technical requirements and gameplay complexity, there can be thousands of these units forming a web of logic units.

Game programmers tend to use graph theory for defining and coding logic units. Each unit is symbolized with a simple geometric shape. A box, a circle, anything… And these units are connected to each other with links.

  “Logic units” (nodes) represent tasks that the player will perform.

  “Links” (lines) represent the relationship between the logic units.

Behaviour Analysis

A node graph architecture is almost identical to an electronic circuit. When you start executing a node graph code, you are actually branching from one component (node, in our case) to an another by the rules you’ve set for the logic units, just like electric current flowing from a resistor to a capacitor. And, as you can guess, this type of signal flow is 100% linear.

When the player accomplishes a task, the node related to that event will be “expired”. In other words, it will be dead. Expired nodes cannot be resurrected. Once they’re done, they will be ignored (skipped) during code execution, forever. – Which is unlikely in electronics! An electronic component, such as a resistor, a diode, etc. cannot be conditionally turned on/off.

Back to 2002 for a “classic” implementation: Flagger

During the “Culpa Innata” development sessions, we precisely knew that we needed a node graph architecture for handling game’s complex execution flow. Many discussions were held on the method of implementation. All members of the core management & development team were expert electric/electronics engineers with no experience in video game production [Reference], but me! As a video game programmer, my perspective towards node graph theory was naturally very different, contrary to their classical approaches. I wasn’t thinking in terms of voltage, current, etc., but focused on just one thing: optimized code execution.

Thanks to my Zilog Z80 and Motorola 68000 assembly language programming background, I offered the term “Flag” for the base logic unit (node), and teamed up with Mr. Mete Balcı for 3 weeks. In December 2002, we developed a tool called “Flagger”.

Pros and Cons

Flagger was a C++ code generator with a very handy visual interface similar to UE4’s current Blueprint approach. Using Flagger, we were able to add nodes, connect them to each other, program the logic behind the nodes/links, and even take printout of the whole node graph scenario. When the visual logic design process was over, it was just a matter of selecting “Generate C++ code” from the menu, and source code was generated within minutes.

Over the following years, Flagger evolved into a more sophisticated development tool capable of handling various scenarios. Although it was a very handy tool and saved many hours during “Culpa Innata” sessions, there were a few problems with the classical node graph theory that the implementation was based on;

  Flags were single threaded. Only one node was allowed to execute at a time. No multi-threading.

  Flags were expirable. When a task was done, related flag (node) was marked as “expired”, not deleted for the sake of logic integrity.

  Flags were not reusable. Once they were expired, there was no way of resurrecting them. – Inefficient memory usage, thanks to hundreds of expired nodes.

  Flags were heavily loaded with variables. Too many dialogue related “customized” variables were defined for special cases (exceptions). – Inefficient memory usage, once again.

  Flag execution flow wasn’t well optimized because of node-tree search algorithm. The more nodes we had, the longer it took to accomplish the search.

  Flag execution was linear. When a node was expired, the graph code was first searching for related nodes and then retriggering the whole diagram from the beginning, like an electronic circuit simulator. – Well, that was ideal for modeling a circuit, not for developing a video game!

A Modern Approach: 3-bit Worker!

13 years later, I have once again found an opportunity to dive into node graph theory, and just completed implementing a new architecture for my latest video game development project. Unlike Flagger, it is something extraordinary! It is very… atypical, unconventional, unorthodox… Well, whatever… You got it 😉

First of all, it has nothing to do with classical electric/electronic circuit theory. This time, I’m on my own, and approaching the problem as a software engineer. Everything I designed/coded is based on game requirement specifications. In other words, it is implemented with “practical usage” in mind.

  I have defined the basic logic unit (node), as a “worker”.(Due to functional similarities, I simply borrowed this term from Web Workers.)

  A worker is a background task with adjustable priority settings. It performs/responds like a hardware interrupt.

  Each worker is multi-threaded.

  Depending on conditional requirements, a worker can expire and/or live forever. If expired, it can be resurrected and/or reinitialized, while preserving its previous state. So, a worker is a 100% reusable node.

  Each worker uses only 3-bits! No additional variables, no references, nothing else. – (If necessary, a worker offers flexible architecture for additional variables. However, I find it totally unnecessary. 3-bits are more than enough!)

  Workers are object oriented. They can easily be inherited.

  Inherited workers don’t need additional logic variables. All child workers share the same 3-bit information that they inherited from their parents!

  Each worker has a time dependent linear workflow. Just like a reel-to-reel tape recorder, it can be played, paused, slowed down, accelerated, fast forwarded, rewinded, and stopped.

  Workers can be non-linearly linked to other Workers! Which means, node-tree search algorithms are no more necessary. There is no “main loop” for executing nodes! Code execution is pre-cached for optimum performance.

  Workers are optimized for event driven methodology. No matter how many concurrent active workers (threads) you have in the scene, there is practically no CPU overhead. Ideal for mobile scenarios.

  Workers are managed by “Managers”. A Manager is inherited from base Worker node. So, any worker can be assigned as a Manager.

  Workers can communicate with each other and access shared variables via Managers.

  Whole architecture is 100% platform independent. For a showcase, I’ve implemented it for Unreal Engine 4 using C++ and Blueprints. It can easily be ported to other game engines; such as Unity, CryEngine, etc.

  And, most important of all, everything is meticulously tested. – It’s working as of today 🙂

Any drawbacks?

Sure… Due to complexity of comprehending “a set of non-linearly linked time dependent linear nodes”, debugging can be a nightmare. As always, designing simplified and organized logic sets reduces potential problems. – I keep my logic sets neat and tidy 😉

So, what’s next?

Well, to be honest, since all theoretical stuff is done, I’ll switch to game content development. I am quite sure that I’ll keep on adding/removing things to my 3-bit node graph architecture. I will keep on improving it while preserving its simplicity, for sure.

“It is vain to do with more what can be done with less.” – (William of Ockham)

An unexpected surprise made my day!

Since the day I noticed his Star Wars, Alien and Predator sketches, I have always admired Tuncay Talayman’s artwork.

It has been a privilege –and a lot of fun– working with him during Culpa Innata development sessions (2001-2003). Even after all those years, his continuous passion for improving his techniques and seeking new ways of artistic expressions, still surprises me. The portrait below is one of them 😉

What a lovely surprise… Thank you very much Tuncay!

Tuncay Talayman's portrait of Mert Börü

Kitaro’s “Symphony Live in Istanbul” CD announced

Recorded Live at the Halic Congress Center in Istanbul, Turkey over two evenings in March of 2014, Grammy and Golden Globe winning artist Kitaro‘s “Symphony Live in Istanbul” CD is announced!

Commenting on the groundbreaking event, Kitaro noted “I am extremely grateful that my dream of performing in Istanbul finally came true. It was a once in a lifetime experience and in addition to my many experiences; I met a host of great people from Istanbul and the neighboring countries.  As a remembrance of my amazing music caravan and as a tribute to those I encountered along the way, I recorded this musical experience and performance as a CD.  It is my gift to everyone, in Istanbul and around the world, to experience and enjoy.”

Thanks to once-in-a-lifetime concert experience we had in Istanbul, Börü family is more than happy to pre-order the album 🙂

[ Börü family at Kitaro’s “Live in Istanbul” concert ]

This album includes Kitaro’s Golden Globe award-winning theme from the Oliver Stone film “Heaven & Earth”, music from his critically acclaimed Kojiki album and “Silk Road” soundtrack as well as two compositions from his Grammy award-winning album “Thinking Of You”.  New material includes a previously unreleased composition; “Kokoro – (Part II)”.

Looking forward to seeing Kitaro in Istanbul, again…

A glimpse of Fractals in CAD+ magazine

In the late 80s and early 90s, I was more than obsessed with fractals! Since the day I saw beautiful landscape pictures rendered with Vista on my humble Amiga 500, I was addicted to writing simple mathematical routines producing complex images. The philosophy behind fractal math was based on “harmony of contradiction”. You may think of it as a mathematical case where “simplicity defines complexity”.

Continue reading A glimpse of Fractals in CAD+ magazine

Who’s Afraid of Visual Basic?

“Kim Korkar Bilgisayardan? – Visual Basic” (“Who’s Afraid of Computers? – Visual Basic”) is a computer language programming book that I have written for students and amateur programmers. It was published in February 1997 by Pusula Yayıncılık, as an introduction to Microsoft’s then-popular rapid application development tool; Visual Basic 4.0.

Continue reading Who’s Afraid of Visual Basic?

“Paradise Lost” found!

“Paradise Lost” is the first commercial Amiga game designed and developed in Turkey. It was proudly produced by Ahmet Ergen and me, and released on 4 floppy disks in December 1991.

Although it was a phenomenal technical achievement in terms of setting the bar for game development in Turkey by the early 1990s, it was a commercial failure. Thanks to problematic distribution channel and no media support, only a few hundred copies were sold. And, as far as I know, none of them have survived. It is a game that is no longer known to exist in any private collections or public archives. Long lost and forgotten, until now!

Continue reading “Paradise Lost” found!

“Far Beyond The Endless” remix released

Moist is electronica producer, artist, songwriter & remixer David Elfström Lilja from Söderhamn, Sweden.

As a remixer Moist has made a bunch of remixes for artists like Pet Shop Boys, Butterfly Boucher, Red Snapper, Erasure, Agnes, Sophie Rimheden, Håkan Lidbo, Tomas Andersson Wij and many more.

This time, he is not remixing, but gets remixed! – Today, Moist is releasing “Far Beyond The Endless” 6-track digital single, including my remix on the last track!

Continue reading “Far Beyond The Endless” remix released

An encounter with Darth Vader!

Yes, it is my destiny 🙂

Finally, meeting Mr. Dave Prowse (aka Darth Vader in the original Star Wars trilogy) at D&R Astoria, Istanbul.

Mr. Dave Prowse and his humble servant!
Mr. Dave Prowse and his humble servant!

Due to release of official Darth Vader comic series, he is invited to Istanbul by a local publisher. It was announced a few months ago, and I was waiting for him since then…Certainly worth the wait! Such a kind man, and a true English gentleman with a big warm heart. He is an authentic Jedi knight, actually!  –  “At your service, my Lord!”

[ more photos from this event ]