Recently, techniques developed in the field of computer graphics and virtual reality have been applied to many environments, with the result that measuring the 3D shapes of real objects has become increasingly important. However, few methods have been proposed to measure the 3D shape of transparent objects such as glass and acrylics. In this paper, we introduce three methods that estimate the surface shape of transparent objects by using polarization analysis. The first method determines the surface shape of a transparent object by using knowledge established in the research field of thermodynamics. The second method determines the surface shape of a transparent object by using knowledge established in the research field of differential geometry. The third method gives an initial value of the surface shape and then determines the true surface shape of a~transparent object by iterative computation. At the end of the paper, we discuss the advantages and the disadvantages of these three methods.