Ultimate Presentation

Coordination with Behavior Trees: Synchronizing Multiple Agents in CryEngine 2

Ricardo Pillosu on July 22, 2009

As behavior trees become the implementation of choice for individual game characters, game developers are increasingly turning towards them to coordinate multiple agents. Ricardo Pillosu's talk at the Paris Game AI Conference 2009 focused on his recent experience applying the behavior tree paradigm on top of the CryEngine 2's existing AI system, and in particular to coordinating multiple AI agents simulate group tactics.

About Ricardo

Ricardo Pillosu is a Lead Programmer at Crytek GmbH currently working on an undisclosed project. He previously was an AI Programmer and built a behavior tree on top of CryEngine2's AI, in particular to support multiple AI coordination and simulation of group tactics. He also implemented low-level AI actions integrated with Lua, and worked on the simulation of AI characters with emotions.

Audio/Video Recording

Topics Index

  • 0:00:59 — Introduction to Crysis (Video) Watch ?

  • 0:03:00 — Contributors and Responsibility Watch ?

  • 0:04:58 — Motivation for Crytek Watch ?

  • 0:07:50 — The Importance of Ease of Use Watch ?

  • 0:09:18 — Transition to Behavior Trees Watch ?

  • 0:11:50 — Agent Knowledge Example Watch ?

  • 0:13:00 — Debugging Behaviors Watch ?

  • Behavior Tree
  • 0:13:39 — Condition Check and Actions Watch ?

  • 0:14:52 — Child Execution Watch ?

  • 0:16:23 — Decoupling of Condition and Action Watch ?

  • 0:17:43 — Evaluation Order Watch ?

  • 0:18:57 — Combat Tree Structure Watch ?

  • 0:21:05 — Example Action Game Scenario Watch ?

  • 0:25:48 — Question: Re-Evaluation Watch ?

  • 0:27:38 — Question: Production Issues Watch ?

  • 0:31:05 — Question: Preparation Animations Watch ?

  • 0:33:13 — Implementing Custom Behaviors Watch ?

  • Coordination
  • 0:34:50 — Synchronized Behavior Change Watch ?

  • 0:36:32 — Tactics Manager Step by Step Watch ?

  • 0:37:45 — Homework: Where to Put Flanking? Watch ?

  • 0:41:06 — Tactical Monitoring Watch ?

  • 0:44:00 — Coordinating Agents: Hints Watch ?

  • 0:48:07 — Coordinating Agents: Examples Watch ?

Downloadable Version

Here's a specialized format for you to download and play offline via a portable player:

Coordinating Agents with Behavior Trees — Video
Ricardo Pillosu
Download MOV (QuickTime)

The MP3 file below is better quality than the streaming video above, and is a perfect candidate for listening to via a portable player (96 Kbps). The OGG file is the highest quality of all (128 KBps). You can download them both here:

The slides used during the presentation are available here:

Coordinating Agents with Behavior Trees — Slides
Ricardo Pillosu
Download PPT or PDF

Here is the text version of the document, transcribed by Melanie C. and Pedro Melendez, for you to download, print and read away from the computer:

Coordinating Agents with Behavior Trees — Transcript
Ricardo Pillosu
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If you have any questions feel free to post them below, or in the forum thread associated with this post!

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