@article {IOPORT.06081830,
    author       = {Elber, Gershon and Kim, Yong-Joon and Kim, Myung-Soo},
    title        = {Volumetric Boolean sum.},
    year         = {2012},
    journal      = {Computer Aided Geometric Design},
    volume       = {29},
    number       = {7},
    issn         = {0167-8396},
    pages        = {532-540},
    publisher    = {Elsevier Science Publishers B.V. (North-Holland), Amsterdam},
    doi          = {10.1016/j.cagd.2012.03.003},
    abstract     = {Summary: Boolean sum is a well-known surface construction operation [{\it E. Cohen}, {\it R. F. Riesenfeld} and {\it G. Elber}, Geometric modeling with splines: an introduction. Natick, MA: A. K. Peters. (2001; Zbl 0980.65016)]. In the light of the growing interest in trivariate B-spline and NURBs, for example in Isogeometry analysis, in this work we extend this operator for trivariate volumetric elements. Consider six arbitrary tensor product B-spline and/or NURBs surfaces that share boundaries along a cube-like topology. The volume that is enclosed by these six surfaces is parameterized using a volumetric extension of the Boolean sum for surfaces, while the boundaries of the proposed volumetric extension interpolate the six input surfaces. Finally, a generalization of the Boolean sum idea is presented for the general multivariate case.},
    identifier   = {06081830},
}