Constraining the three-dimensional light distribution of the galaxy components, and therefore their intrinsic shape, is a crucial piece of information in our understanding of how galaxies form and evolve. Several studies addressed the intrinsic shape of elliptical galaxies, dealing with the distribution function of the intrinsic axial ratios of the whole population through statistical analysis of their apparent flattenings. However, deprojecting the apparent shape of an elliptical galaxy into its intrinsic shape represents a typical ill-posed problem, caused by the lack of observational constraints on the three Euler angles that provide the transformation. On the contrary, in disk galaxies it is possible to derive the intrinsic shape of individual galactic substructures (i.e., bulges, bars, etc.) because of the presence of the disk component. Thus, the measurements of the intrinsic shape of galactic components might provide a fundamental additional constraint to separate bulge types (i.e., classical vs disk-like), understand the co-evolution of bulges and bars, as well as set limitations for future numerical simulations willing to reproduce realistic galaxies.