BRIX5

        ret.cell(0, 0) = 1-(2*(_y*_y))-(2*(_z*_z));

        ret.cell(0, 1) = (2*_x*_y)-(2*_w*_z);

        ret.cell(0, 2) = (2*_x*_z)+(2*_w*_y);

        ret.cell(1, 0) = (2*_x*_y)+(2*_w*_z);

        ret.cell(1, 1) = 1-(2*(_x*_x))-(2*(_z*_z));

        ret.cell(1, 2) = (2*(_y*_z))-(2*(_w*_x));

        ret.cell(2, 0) = (2*(_x*_z))-(2*_w*_y);

        ret.cell(2, 1) = (2*_y*_z)+(2*_w*_x);

        ret.cell(2, 2) = 1-(2*(_x*_x))-(2*(_y*_y));