Stella is a

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

available in three versions (Great Stella, Small Stella and Stella4D). It was created by Robert Webb of

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. The programs contain a large library of

polyhedra In geometry, a polyhedron (: polyhedra or polyhedrons; ) is a three-dimensional figure with flat polygonal faces, straight edges and sharp corners or vertices. The term "polyhedron" may refer either to a solid figure or to its boundary su ...

which can be manipulated and altered in various ways.

Polyhedra

Polyhedra in Great Stella's library include the

Platonic solid In geometry, a Platonic solid is a Convex polytope, convex, regular polyhedron in three-dimensional space, three-dimensional Euclidean space. Being a regular polyhedron means that the face (geometry), faces are congruence (geometry), congruent (id ...

s, the

Archimedean solid The Archimedean solids are a set of thirteen convex polyhedra whose faces are regular polygon and are vertex-transitive, although they aren't face-transitive. The solids were named after Archimedes, although he did not claim credit for them. They ...

s, the Kepler-Poinsot solids, the

Johnson solid In geometry, a Johnson solid, sometimes also known as a Johnson–Zalgaller solid, is a convex polyhedron whose faces are regular polygons. They are sometimes defined to exclude the uniform polyhedrons. There are ninety-two Solid geometry, s ...

s, some Johnson Solid near-misses, numerous compounds including the

uniform polyhedra In geometry, a uniform polyhedron has regular polygons as faces and is vertex-transitive—there is an isometry mapping any vertex onto any other. It follows that all vertices are congruent. Uniform polyhedra may be regular (if also fac ...

, and other polyhedra. Operations which can be performed on these polyhedra include

stellation In geometry, stellation is the process of extending a polygon in two dimensions, a polyhedron in three dimensions, or, in general, a polytope in ''n'' dimensions to form a new figure. Starting with an original figure, the process extends specific ...

, faceting, augmentation, dualization (also called "reciprocation"), creating

convex hull In geometry, the convex hull, convex envelope or convex closure of a shape is the smallest convex set that contains it. The convex hull may be defined either as the intersection of all convex sets containing a given subset of a Euclidean space, ...

s, and others. All versions of the program enable users to print

net NET may refer to: Broadcast media United States * National Educational Television, the predecessor of the Public Broadcasting Service (PBS) in the United States * National Empowerment Television, a politically conservative cable TV network ...

s for polyhedra. These nets may then be assembled into actual three-dimensional

polyhedral model The polyhedral model (also called the polytope method) is a mathematical framework for programs that perform large numbers of operations -- too large to be explicitly enumerated -- thereby requiring a ''compact'' representation. Nested loop progra ...

s of great beauty and complexity.

Stella4D

In 2007, a Stella4D version was added, allowing the generation and display of four-dimensional polytopes (

polychora In geometry, a 4-polytope (sometimes also called a polychoron, polycell, or polyhedroid) is a four-dimensional polytope. It is a connected and closed figure, composed of lower-dimensional polytopal elements: vertices, edges, faces (polygons), a ...

), including a library of all convex uniform polychora, and all currently known nonconvex star polychora, as well as the uniform duals. They can be selected from a library or generated from user created polyhedral

vertex figure In geometry, a vertex figure, broadly speaking, is the figure exposed when a corner of a general -polytope is sliced off. Definitions Take some corner or Vertex (geometry), vertex of a polyhedron. Mark a point somewhere along each connected ed ...

files.

Features

Stella provides a configurable workspace comprising several panels. Once a model has been selected from the range available, different views of it may be displayed in each panel. These views can also include measurements, symmetries and unfolded nets. A variety of operations may be performed on any polyhedron. In 3D these include:

faceting Stella octangula as a faceting of the cube In geometry, faceting (also spelled facetting) is the process of removing parts of a polygon, polyhedron or polytope, without creating any new Vertex (geometry), vertices. New edges of a faceted po ...

, augmentation, excavation, drilling and dualising. Other features include spring network relaxation, generation of the convex hull, and generation of cupolaic blends and related figures.

Release history

* v1.0 – 20 August 2001 – First release of Stella ** v1.1 – 14 January 2002 * v2.0 – 12 September 2002 ** v2.8.7 – 16 November 2004 * v3.0 – 12 June 2005 ** v3.5.1 – 10 May 2006 * v4.0 – 13 March 2007 – (Including new "Stella4D") ** v4.4 – 11 January 2008 * v5.0 – 30 September 2012 ** v5.4 – 10 May 2014

References

* * * (Note: journal was back-dated. Paper actually written 2003)

External links