Awesome
Symmetries
This playground book gives a quick insight into the symmetry groups of 3-dimensional objects like the platonic solids. The user can play around with the platonic solids (which are rendered by a custom-written renderer). Additionally, they can experience the rotational symmetries of select solids. The icing on the cake is the duality operation - users can interactively see the generation of dual platonic solids.
This playground was created within one week (7 days) for Apple's WWDC 2020 Swift Student Challenge. To run this playground you need the Swift Playgrounds app (either for macOS or iPadOS). For best experience, use a device with a large screen.