The concept Kinetic::InstantaneousKernel covers models that act as adaptors allowing CGAL static data structures to act on snapshots of kinetic data. Different methods for evaluating predicates are used depending on whether time is set using an NT or a Time object. Evaluating predicates when time is the former is much cheaper.


A number type which can be used to represent the current time. This must be a ring or field type.

The type used to represent the current time. This type must be comparable.


Time a.time () Return the current time.

NT a.time_as_nt () Return the current time as an NT. As a precondition, time_is_nt must be true.

bool a.time_is_nt () Return true if the last time time was set, it was using an object of type NT.

void a.set_time ( Time) Set the current time to have a certain value. All existing predicates are updated automatically.

void a.set_time ( NT) The the current time to be an instance of NT. With this more efficient techniques can be used. time_is_nt() must be true.

Static_object a.static_object ( Key) Return a static object corresponding to the kinetic object at this instant in time. time_is_nt() must be true.

Has Models