## AlphaShapeTraits_3

### Definition

The concept AlphaShapeTraits_3 describes the requirements for the geometric traits class of the underlying Delaunay triangulation of a basic alpha shape.

### Generalizes

DelaunayTriangulationTraits_3

In addition to the requirements described in the concept DelaunayTriangulationTraits_3, the geometric traits class of a Delaunay triangulation plugged in a basic alpha shapes provides the following.

### Types

AlphaShapeTraits_3::NT
| A number type compatible with the type used for the points coordinate.
AlphaShapeTraits_3::Compute_squared_radius_3
| An object constructor able to compute the squared radius of the smallest circumsphere of 4 points p0, p1, p2, p3, the squared radius of the smallest circumsphere of 3 points p0, p1, p2, and the squared radius of smallest circumsphere of the points p0, p1.

### Creation

AlphaShapeTraits_3 traits;
| Default constructor.

### Access Functions

Compute_squared_radius_3
| traits.compute_squared_radius_3_object ()

### Has Models

All CGAL kernels.
CGAL::Exact_predicates_inexact_constructions_kernel (recommended)
CGAL::Exact_predicates_exact_constructions_kernel
CGAL::Filtered_kernel
CGAL::Cartesian
CGAL::Simple_cartesian
CGAL::Homogeneous
CGAL::Simple_homogeneous