COMPUTING MOMENTS OF OBJECTS ENCLOSED BY PIECEWISE POLYNOMIAL SURFACES

Combining a polynomial free-form surface representation with Gauss' di vergence theorem allows efficient and exact calculation of the moments of the enclosed object. For example, for a cubic representation, volu me, center of mass, and the inertia tensor can be computed in seconds even for complex objects with several thousand patches while changes d ue to local modification of the surface geometry can be computed in re al-time as feedback for animation or design. Speed and simplicity of t he approach allow solving the inverse problem of modeling to match pre scribed moments.