public void setZero ( ) { xx = 0.0 ; yx = 0.0 ; zx = 0.0 ; xy = 0.0 ; yy = 0.0 ; zy = 0.0 ; xz = 0.0 ; yz = 0.0 ; zz = 0.0 ; xd = 0.0 ; yd = 0.0 ; zd = 0.0 ; }
Sets all elements to 0 thus producing and invalid transformation .