my_model(x[3], a[1]) { array x0[6], y0[6], z0[6], d[6], b[6]; x0 = [-7., -6.0, -4., -2.0, 0., 6]; y0 = [-7, -4, -7, -4, -2, 1]; z0 = [-7, -6, -4, -2, 0, 4]; b = [1, 1, 1, 1, 1, 1]; d = [2.5, 3, 3.3, 4, 3.5, 3.5]; my_model = hfMetaball(x,x0,y0,z0,b,d,0.18); }