This section describes the algorithms for calculating the
cloth configuration during manipulations. First the
immediate goal position for each cloth vertex is computed
in response to user input, and then relaxation steps adjust
the positions to preserve basic cloth constraints such as
prevention of penetration and limiting stretch. These two
phases are actually closely integrated, but we describe them
separately for clarity. We first discuss how to calculate
immediate goal positions for cloth vertices during wrapping
and surface dragging, and then describe how to preserve the
cloth constraints.
The body and the clothes are represented as standard
triangular meshes, and each cloth edge has an associated
rest length. The parameters defining the behavior of the
algorithms must be set accordingly to the characteristics of
the target polygonal models. Our current implementation
uses body models of 1.0~2.0 units in height and width that
consist of a few thousand polygons.