Understanding behavior

Why behavioral AI matters

About 50% of games today feature non-player characters (NPCs). Sometimes they are just images used to drive a story, but more often they are animated 2D or 3D characters controlled by some form of AI.
Among gamers and industry professionals, there's a broad consensus that character AI hasn't seen fundamental improvements in quality since roughly 2005. The result is that characters today still feel scripted, uncanny and robotic.
At VIRTUAL BEINGS, we believe that this lack of innovation is a creative bottleneck for games and virtual worlds as well as an opportunity for those willing to approach the problem with a fresh perspective.

The 12 principles of behavior

Almost every student of character animation today learns about Disney's famous 12 principles of animation. They are timeless laws for how to make animated characters feel believable and engaging.
In many ways, the art of creating AI characters can be seen as an extension of character animation. Disney's principles still apply, yet they also need to be extended because AI characters interact with the virtual world they inhabit.
Based on more than 20 years of academic research and in-house R&D, we have identified 12 principles of behavior. They apply not only to the behavior of real animals (including humans), but also to that of cartoony or stylized ones.
KuteEngine™, our in-house tech for behavioral AI, powers 3D characters that live up to all 24 principles. This allows them to feel alive and to act like first-class citizens of the virtual world they inhabit.
  1. 1.
    Behavior is observable - Only physiological events that are perceivable without special instruments, such as an MRI scanner, are considered behavior.
  2. 2.
    Behavior is continuous - Agents behave all the time, from birth to death. Even when a living agent appears to be doing nothing, its motionlessness is generally the result of regulated stasis.
  3. 3.
    Behavior is adaptive (responsive, interactive) - Behavior is how agents relate to the world, and that is why all behavior needs to be interactive.
  4. 4.
    Behavior is constrained - Context imposes many constraints on behavior, in the form of conditions (physical, functional, ...) that shape it in various ways.
  5. 5.
    Behavior is sequenced - Agents assemble their behavior from parametric motion sequences (walking, scratching, dancing ...) that are executed as chunks.
  6. 6.
    Behavior is interruptible - Even the most perfectly planned behaviors won't always survive first contact with reality.
  7. 7.
    Behavior shows patterned variation - Two behaviors can be similar, but they are never fully identical.
  8. 8.
    Behavior is hierarchical - Bodies and their control mechanisms are organized in hierarchies, and subordinate parts (like toes) depend on superior ones (like feet).
  9. 9.
    Behavior is parallel - A single agent often does more than one thing at a time.
  10. 10.
    Behavior is cognitively caused - Agents have nervous systems that control muscles and that display a high degree of organization.
  11. 11.
    Behavior is cognitively monitored - During execution, behavior often needs to be adapted, which requires continuous monitoring.
  12. 12.
    Behavior is cognitively readable - Agents observe other agents and draw conclusions about their emotions and intentions.