A working prototype for browsing PDC projects as shells, cores,
occlusion systems, and repair fields. Use the orbit for quick spatial
browsing, or switch to the index for a compact project list.
selection logic
One geometry, four readable layers.
The selector treats sphere-based design as a field of related behaviors:
enclosure, structure, viewshed control, and urban repair. The goal is not
to make every project look spherical, but to show which design problem the
sphere is solving.