Preserving form features in interactive mesh deformation

Interactive mesh deformation that preserves differential properties is a promising technique for the design of mechanical parts such as automobile sheet-metal panels. However, existing methods lack the ability to manipulate the form features and hard constraints that are commonly used in engineering applications. In this paper, we propose a new deformation framework that precisely preserves the shapes of form features during deformation. Geometrical shapes are interactively deformed so that mean curvature normals are approximately preserved in a least-squares sense and positional constraints and form-feature constraints are precisely satisfied. In our system, the combination of soft and hard constraints is solved using the Lagrange multiplier method. We also show how to constrain the motion of a form feature on a plane or a straight line using linear constraints. The implemented system achieves a real-time response for constrained deformation.