The class Kinetic::Enclosing_box_3<Traits> keeps the points in the simulation inside of a box. Whenever the points come close to the wall of the box they bounce off of the wall.
Note that, in general, points hit the wall of the box at times which are not easily represented by standard (rational) number types. The resulting trajectories would also have nonrational coefficients, complicating and slowing the simulation. In order to handle this, the Kinetic::Enclosing_box_3<Traits> bounces the points at the nearest easily representable time before the point would leave the box.
#include <CGAL/Kinetic/Enclosing_box_3.h>
 
The number type used to represent the walls of the box and perform calculations. Generally this is Traits::NT.

 
This constructs a bounding box with the dimensions specified by the last 6 arguments. They are optional and will take the values ± 10 if omitted.
