A system for three-dimensional (3-D) facial animation, including a base
3-D surface model representing a human face, and a set of displacement
fields representing surface motion patterns associated with muscle
movements. Each displacement field is a displacement vector varying over
vertices of the base surface model and an intensity variable. Both the
base surface model and displacement fields are acquired from a live
subject by 3-D acquisition. The data are acquired using a surface
acquisition system, capable of measuring the coordinates of a set of
points on the subject's face and reconstructing the facial surface as a
surface model. The base surface model is acquired by reconstructing the
surface of the subject's face in the neutral pose. Each displacement
field is acquired by reconstructing the surface of the subject's face in
a series of poses of a muscle movement at increasing intensities. This
results in a sequence of surface models exhibiting the changing shape of
the face over the progress of the muscle movement. The displacement field
is derived by calculating displacements at each selected intensity value
and then interpolating over the known displacements.