Organizing Principles
Separating Plane (geometry only)
Animation (geometry only)
Unless otherwise noted, all these organizing principles have at least 2 corresponding organizer classes, one for feature representations, the other for geometry.
Three of them - union, spatial index, and perimeter - can also be applied to topological organizations.
To understand a given principle for any one case - whether geometry, features, or topology - is to understand it for all cases.