“…Let F , G, H be the parameterized values of a grid point in the I, J, and K indices. The 1-D TFI in the K-direction is simply (2) where ∆E refers to the deformation of an edge, which in this example varies in the k-index, while P 1,1,1 and ∆P 1,1,kmax are the deformations of the two corner points of the edge. The 2-D TFI is defined as (for a surface in the I=1 plane):…”