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3.3. Eye-Tracking For Interaction
Figure 3.3: Multiple textures on a single mesh to obtain variety in character representations.
3.2.4 Scripts
As previously mentioned, the existing architecture developed in VRLab allowed the use of
Python scripts in order to give instructions as to how the scenarios should unfold. We have
thus created different scripts for the various scenarios in order to instruct the characters on
what they should do. A simple view of the general animation loop is shown in Algorithm 3.1:
Before launching the script containing the general animation loop, an initialization script
is executed in order to define the characters which are present in the scene and their original
posture. Now that we have explained how we setup our various characters in various scenarios,
we discuss in more detail how we animate them and assign them different behaviors.
3.3 Eye-Tracking For Interaction
In order to use VR as a tool in CBT, and more specifically, in the treatment of phobias or
other social related problems, patients need to feel present in the VEs and feel the presence of
its characters. When it comes to characters, in order for the sense of presence to be increased,
both their representation and behavior have to be worked on in parallel, otherwise, sense of
presence decreases [Garau et al., 2003]. This is also known as the “uncanny valley” effect,
which has first been presented in the field of robotics [Mori, 1970]. This need is especially
true in the case of social phobia, since patients need to feel as if they were in a real situation;
they need to experience the anxiety they would experience in-vivo and feel that they are
really facing a character that understands their presence. In other words, since we are already
quite good in virtual human representations, what is needed is an increase in realism in their
behaviors. The difficulty is that as humans, we are experts in human behavior. It makes it
much harder to create credible characters. Much research has already been conducted in this
aim, such as speech synthesis, character modeling or animation.
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