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Chapter 4. Simulating Visual Attention for Crowds
empirical. It could therefore be interesting to try to determine them using motion capture
and eye-tracking to improve realism. However, we believe that the amount of work needed
to precisely determine each joint contribution would be tremendous in comparison to the
added value this could convey.
Interest point scalability. A major advantage of our method is that it is extensible. We
could easily add extra criteria such as color or contrast without having to modify the existing
architecture. Another interesting aspect would be to provide entities with multiple interest
points. A character with very flashy shoes would then attract attention to his feet. Similarly,
a character waving his hand would attract attention if we consider the body parts’ relative
velocity. Finally, sound could also be added as it has a very strong attention capture potential.
4.7 Conclusion
In this chapter, we introduced a novel method to enhance crowd animation realism by adding
attention behaviors to the characters composing it.
We first proposed an automatic interest point detection algorithm which determines, for
each character, where and when it should look. We additionally presented an extensible
and flexible set of criteria to determine interest points in a scene and a method to combine
them. Our method also allows the fine-tuning of character attention behaviors by introducing
an attention parameter as well as the possibility to modify the relative importance of each
criterion if desired.
Secondly, we introduced a robust and very fast dedicated gaze IK solver to edit the character
motions. Our solver deals with the spatial and temporal resolution of the gaze constraints
defined by our detection algorithm.
Finally, we illustrated our method with visually convincing results obtained with our
architecture. We believe that gaze behaviors greatly enhance crowd character believability,
and thus, greatly amplify the immersive properties of virtual crowd scenarios in the context
of VRET of agoraphobia. To this extent, the next chapter of this thesis tackles the application
of such gaze behaviors in an immersive environment and with interaction possibilities.
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