  We use an elastic model to explore faceting of solid-wall vesicles with
elastic heterogeneities. We show that faceting occurs in regions where the
vesicle wall is softer, such as areas of reduced wall thicknesses or
concentrated in crystalline defects. The elastic heterogeneities are modeled as
a second component with reduced elastic parameters. Using simulated annealing
Monte Carlo simulations we obtain the vesicle shape by optimizing the
distributions of facets and boundaries. Our model allows us to reduce the
effects of the residual stress generated by crystalline defects, and reveals a
robust faceting mechanism into polyhedra other than the icosahedron.
