Direct manipulation of free-form deformations

Fme-form defommtion (FFD) is a powerful modeting tool, but contmtling the shape of an object under complex deformations is often ~cult.'fhe interface to FFD in most conventional syetems simply mpments the unddying mathematics directly, ur3ent&acdbe deformations by manipulating control points.lhe difEculty in controlling shape precisely is largely due to the control pcdnte being extmneous to the objec~the deformed object does not follow the control pointn exactly.In addition, the number of &gmes of freedom pre@entedto the user cm be ovenvhelming.We present a method that allows a uacr to control a fme-form deformation of an object by manipulating the object dhectly, leading to better contmd of the deformation and a more intuitive interface.