We present a shape deformation approach which preserves volume, prevents self-intersections and allows for exact control of the deformation impact. The volume preservation and prevention of selfintersections are achieved by utilizing the method of Vector Field Based Shape Deformations. This method produces physically plausible deformations efficiently by integrating formally constructed divergence-free vector fields, where the region of influence is described by implicitly defined shapes. We introduce an implicit representation of deformation boundaries, which allows for an exact control of the deformation: By placing the boundaries directly on the shape surface, the user can specify precisely where the shape should be deformed and where not. The simple polygonal representation of the boundaries allows for a GPU implementation, which is able to deform high-resolution meshes in real-time.