def translate(x, y, z)
      @x += x.to_f
      @y += y.to_f
      @z += z.to_f
    end
def translate(x, y, z)
      @x += x.to_f
      @y += y.to_f
      @z += z.to_f
    end
Moves the coordinate according to the given offset vector.

 @param [Float] x the offset along the x axis (in units of mm)
 @param [Float] y the offset along the y axis (in units of mm)
 @param [Float] z the offset along the z axis (in units of mm)