Learn about the design tricks that help bring the Darwinians to life in this 1h20 interview with Chris Delay, Lead Designer and Director at Introversion — the developer of Darwinia and Multiwinia. Chris goes into details about how instinctive behaviors work and they way they brought the Darwinians to life. He also talks about implementation of the behaviors, key challenges, performance and optimization to get 2,000 entities battling in Multiwinia. The high-level strategy of the opponent AI is also explained in detail.

This audio/video recording was published on January 31, 2009 for AiGameDev.com Premium members. To celebrate Introversion's release of Darwinia+ this week, it's available free for Insiders signed-up to the site!

Last weekend, the Global Game Jam was held worldwide and we took the opportunity to turn it into an AI Marmalade. (For those of you that still don’t get the breakfast joke: jam, marmalade. See what I did there?) Part of the AiGameDev.com “team” of contributors was available on Saturday and Sunday — Radu, Richard, and partly Nick — and I (Alex Champandard) made some changes in my usual schedule for the weekend, and we built a stealth game!

As a base for the implementation, we decided to use our AI Sandbox as a framework and build this game on top. The goal of the AI Sandbox, beyond just demonstrating AI algorithms and techniques, is to be a good prototyping environment for gameplay & AI — so we figured this would be a good stress test! (The AI Sandbox is currently only available to Premium members, but there's now an official site you can visit!)

NOTE: Parts of this article were written by Radu Septimiu Cristea, who was the main driving force behind the coding this weekend. I'll post a video of the game after the next release of the AI Sandbox, which will include the source code.

Blackboards have increasingly become a key part of almost every game's AI architecture. They help maximize computation time while reducing spikes, as well as helping decouple the behavior from the acquisition of information. However, getting this part of the system right involves finding a good knowledge representation...

Find out exactly how in this 1h masterclass with Damian Isla, Lead AI Programmer on HALO 2 and 3. He'll explain the key motivations for using a blackboard, what role they play in the overall system, how to approach the development process, and what kinds of considerations you need to make while designing your KR.

Building behaviors for a game or simulation is an incremental process involving both the building blocks at the C++ level, and the way they are combined to create the AI. A key part of this process is reviewing and improving the code and the behaviors — and figuring out what the next iteration should be.

This tutorial looks into the behaviors inside the recent release of the Sandbox, in particular the patrol sequence of the red bots and the seeking cover and hiding behaviors of the yellow bots. Both of these are implemented using a behavior tree, and you'll see how these were built and how they can be improved.

The Global Game Jam will take place worldwide this weekend. For those of you participating that are looking for a challenge, fresh ideas to distinguish your game, moral support or help for building your AI, then the AI Marmalade is for you!

AiGameDev.com is proud to announce the AI Marmalade, which will take place on January 29-31 at the same time as the Global Game Jam. You don't have to be at an official Jam location to participate in the Marmalade; in fact you can do it from anywhere!

2009 has been a very important year for game AI as a discipline, possibly one of the most significant yet. I feel a bit less guilty about struggling to keep up with everything just looking at how fast our field is moving!

In this editorial, I'll break down some of the things I expected to happen and what actually did happen. There were also quite a few significant moments this year, as well as a few controversies, which I'll describe in their juicy details as well.

I'd love to hear from you what you thought was significant about 2009, and which moments you think we'll remember in the distant future! Please post a comment below. Also, while you're in the forums, don't hesitate to share some of your predictions for 2010...

In 2004, Botea, Muller, and Schaeffer published the HPA* algorithm (Hierarchical Path-Finding A*), which arguably describes the most popular hierarchical path-finding implementation in the video games industry. One of the most pressing concerns for HPA* is the complexity involved in modifying the graph hierarchy, which is required for connecting arbitrary start and goal nodes. Maintaining a dynamic hierarchy slows performance, and complicates programming and debugging. This paper explains the problems with modifying the graph hierarchy, and then shows how the SHPA* algorithm alleviates these problems by maintaining a static hierarchy. Compared to HPA*, SHPA* is shown to be up to nine times faster in the best case, and about twice as fast for many common cases, while finding paths that are within 4% optimality of HPA*.

This article was written by Alexander Kring, Gameplay Programmer at Nihilistic Software and previously AI Engineer at Electronic Arts. The algorithm described was reimplemented by Nick Samarin in the AI Sandbox, under the guidance of Alex J. Champandard — who also suggested improvements to the algorithm.

Naughty Dog's second game of this console generation, UNCHARTED 2: AMONG THIEVES, received critical acclaim for perfectly blending story telling, high-quality animation and of course gameplay. The game's AI not only allowed the creation of believable buddies that accompany the player (as Nathan Drake) throughout the game, but also supported the variety of enemies in both single player and co-operative modes.

In this 1h30 interview with Christian Gyrling, you'll hear how the new features were implemented, from the implementation of movement via traversal packs, to support for stealth gameplay. You'll also find out all the little details that went into creating the AI for these characters, including the character layering, the integrated pathfinding and obstacle avoidance on the PS3's SPUs, the navigation meshes, the blend tree's functioning, the flat & dynamic structure of the behavior tree, and more...

Those of you who stay up-to-date with AiGameDev.com behind the scenes (on Twitter or in the Forums) know that we've been preparing the 2010 edition of the Paris Game AI Conference for many months already. Organizing last year's event entirely was one of the most rewarding moments of my career, but at the same time it was probably the most difficult thing Petra (Mrs. AiGameDev.com) & I had done so far professionally!

It took a lot of preparation and scouting around before committing to taking the event into its third year, but thanks to your tremendous feedback from 2009 and early support from our Conference Sponsors this year, we're pleased to announce that we'll return to the CNAM in June. In particular, we'd like to thank Autodesk, PathEngine, Spir.Ops and Four Door Lemon for their sponsorship and making it possible!

Read on for details about the conference itself, the call for proposals, and how you can secure your seat at the event...

This 3rd edition is set to be the most controversial — yet fascinating — Annual Awards for Game AI! Let me clarify. The whole procedure, including the nominations and the voting, is done by the community here at AiGameDev.com. Of course, there's a certain editorial process involved in picking the nominees, but the rest is mechanical and just a question of collecting the results.

Typically, I've been able to predict the winners... mostly. This year, however, that wasn't the case! I speculate this could be due to the following reasons:

1. It's been a very constructive year for Game AI, more games deserve the spotlight, and it's harder to separate the candidates.

2. The community is by definition self-selecting and this reflects in the way its best games are chosen...

3. I'm getting older, my taste in games is changing, and everyone voting in the awards thinks radically differently than I do. :-)

It's probably a combination of the three, but the bottom line is that I've decided to include as "Editor's Pick" along with the "Vote Winner" for each award. If anything, I hope this helps shine a spotlight onto more games that are worthy of attention.

Anyway, without further ado...

What common mistakes do new AI engineers make when they first move into game development? How long does it take for them to realize that designers will find edge cases in the code no matter what? And why do all public discussions about game AI end up with programmers complaining about designers? We have the answers, and they are below...

A few weeks ago, the Boston Postmortem held a panel about artificial intelligence in games. It featured Damian Isla, John Abercrombie, Jeff Orkin, and finally Christian Baekkelund as moderator. As you'd expect from the star cast, the discussion was highly stimulating and provided a fresh take on the most commonly addressed topics in our field.

Below in this post you'll find the full transcript of that part of the panel discussion, as well as a festive Thank You from our sponsors!

Welcome to the 3rd Annual AiGameDev.com Awards for Game AI, where the best games of the year are nominated and voted by professionals, enthusiasts, and researchers in artificial intelligence for games. Last week you submitted your nominations, and here are the finalists. You have exactly one week to pick the best candidates by visiting this page. Vote now!

The entries below were chosen thanks to emails, comments, and discussion in our official IRC channel at irc.freenode.net in #gameai. Each nominee had at least two people behind it. Special thanks to Phil Carlisle, Kevin Dill, and Ricardo J. Mendez for their suggestions and descriptions.