A new realistic 3D body representation in virtual environments for the treatment of disturbed body image in eating disorders

In the last few years virtual reality has become an efficient tool for the treatment of eating disorders. One of the main problems in virtual environments finding a realistic body model that can be modified according to a patient's criterion. Several 2D morphing techniques have been used for changing the body of the subject. In this article we present a new method for accurate 3D deformation of a human body model that uses a reduced number of parameters. The original goal was to reform different parts of a 3D human body through geometry. The chosen algorithm is based on a series of boxes around the geometry parts to be changed. Any change in the position of a box vertex is converted to geometry deformation and eventually to oportune displacement of the neighbour boxes. As discontinuities have to be avoided, all boxes have a field of deformation decreasing in intensity as distance increases. To achieve a high grade of realism, a set of user photographs taken from several angles are positioned at the head of the mannequin. Depending on the position of the user, one of the photographs is selected and oriented toward the user. The method is under clinical testing in a virtual reality tool for the treatment of eating disorders. With this method, the model can express several aspects of the way the patients perceive their bodies. Initial clinical results have been very promising.