Multi-Actor Behavior Sequencing in The Sims 4


The Game Developer’s Conference takes place March 17th to the 21st, and The Sims 4 will be present in the form of classes. Below is a description of what developers will take away from the “Multi-Actor Behavior Sequencing” class, the latest of three classes to be added.
GDC Confirmed Classes:
Concurrent Interactions in The Sims 4
AI Postmortems: The Sims 4 and Hearthstone
Multi-Actor Behavior Sequencing in The Sims 4


Brian Bell  |  Senior Software Engineer, Maxis
Location: Room 2020, West Hall
Date: Friday, March 21
Time: 2:30pm-3:30pm
Vault Recording: TBD

As online gaming continues to surge in popularity, simulation complexity increases rapidly and aggressively multi-core platforms become the standard, decoupling game presentation from simulation becomes increasingly important. For The Sims 4, we’ve developed a novel model for rendering high-fidelity synchronized behaviors involving multiple actors, even when driven by a simulation that runs at highly variable and/or low-frame rates, and which potentially communicates with the renderer over a high/variable latency connection.
Historically, such products have often made significant compromises, either by requiring their simulations to run at real-time rates, and forcing extremely rigid synchronization, or by limiting visual quality in critical areas like character animation. Our solution addresses all of these, and is capable of scaling across a variety of game types by offering a core framework for individual game teams to extend and customize.


Attendees will leave this presentation with a working general knowledge sufficient to recreate a basic version of our solution to the problem of high-fidelity, multi-actor behavior in a game with a decoupled simulation, as well as specific solutions to common problems related to character animation in such an environment.

Intended Audience

The primary audience for this presentation is software engineers who are interested in delivering high-quality, multi-actor character animation and other visual behaviors in an online or otherwise parallel game architecture. Prior experience with online (client and server) and simulation-style game development is helpful, but not required.