Interactive specification of 3D displacement vectors using arcball

Direct interactive manipulation of 3D objects is very important in computer graphics. The user interface to deal with this problem poses a difficult problem because of the high number of degrees of freedom involved, associated with the loss of depth in the viewing projection. We introduce a new technique to specify displacement vectors in the three-dimensional space. The technique is built on top of the arcball interface introduced in (Shoemake, 1992). In fact, it constitutes a novel use of the arcball. We also discuss an implementation of the proposed technique in an interactive interface to specify displacement vectors in a widget for surface warping in 3D space.