Hi ton and all i think lattice.c should read like this .... static void calc_curve_deform(Object *par, float *co, short axis, CurveDeform *cd) { Curve *cu= par->data; float fac, loc[4], dir[3], *quat, mat[3][3], cent[3]; ^^^^^^ ........ since where_on_path(ob, ctime1, vec, dir) writes to vec[3] :) Ole