 These nets may then be assembled into actual three-dimensional polyhedral models of great beauty and complexity.In 2007, a Stella4D version was added, allowing the generation and display of four-dimensional polytopes (polychora), including a library of all convex uniform polychora, and all currently known nonconvex star polychora, as well as the uniform duals.They can be selected from a library or generated from user created polyhedral vertex figure files.