Believability, Anticipation, and ... Timing Improving believability through timing manipulation

Having believable interactions between synthetic characters and with people is crucial to the creation of immersive interactive experiences. The believability of such experiences is strongly connected to having the characters express emotions with the correct timing throughout their interaction while retaining the human participants' agency. Unfortunately, most video games adopt static animations, which usually only convey a single emotion throughout, making their expression look artificial, or allowing for greater emotion expressiveness but sacrificing the player's agency. With this work, we propose the creation of a model based on the principles of animation and anticipation that allows for emotion expression during gameplay while retaining the participants' agency. We evaluate our approach using three models. In the first model, characters express emotions in reaction to what happens (this is similar to how games approach emotion expressions), in the second in anticipation of what could happen, and in the third in reaction to what happens given what was anticipated. We tested these models in Adfectus, a 3D arena fighting game, and found improvements in some dimensions relating to the believability of interactions in particular player demographics.