Acis and Galatea (mythology)

The story of the love of Acis and the sea-nymph Galatea appears in Ovid's Metamorphoses. There the jealous Cyclops Polyphemus, who also loves Galatea, comes upon them embracing and crushes his rival with a boulder. His destructive passion comes to nothing when Galatea changes Acis into a river spirit as immortal as herself. The episode was made the subject of poems, operas, paintings and statues in the Renaissance and after.

A story of love and destructive jealousy

Galatea (Γαλάτεια; "she who is milk-white"), daughter of Nereus and Doris, was a sea-nymph anciently attested in the work of both Homer and Hesiod, where she is described as the fairest and most beloved of the 50 Nereids. In Ovid's Metamorphoses she appears as the beloved of Acis, the son of Faunus and the river-nymph Symaethis, daughter of the River Symaethus. When a jealous rival, the Sicilian Cyclops Polyphemus, killed him with a boulder, Galatea then turned his blood into the Sicilian River Acis, of which he became the spirit. This version of the tale occurs nowhere earlier and may be a fiction invented by Ovid, "suggested by the manner in which the little river springs forth from under a rock". According to Athenaeus, ca 200 CE, the story was first concocted as a political satire against the Sicilian tyrant Dionysius I of Syracuse, whose favourite concubine, Galatea, shared her name with the nymph. Others claim the story was invented to explain the presence of a shrine dedicated to Galatea on Mount Etna.

Acis (plant)

Acis is a genus of perennial, herbaceous and bulbous plants in the Amaryllis family (Amaryllidaceae, subfamily Amaryllidoideae). The genus consists of nine species distributed in Europe and Northern Africa.

Taxonomy

Acis was first differentiated from the genus Leucojum by Richard Anthony Salisbury in The Paradisus Londinensis in 1807. In an earlier part of this work, he had used the name Leucojum autumnale for the plant illustrated in plate 21, but when discussing Leucojum pulchellum, illustrated in plate 74, Salisbury noted the differences between the two species and considered them sufficient to put Leucojum autumnale into a new genus, Acis. (However, he did not actually use the name Acis autumnalis, which was published in 1829 by Robert Sweet.) Salisbury did not explain the origin of the name Acis beyond describing it as a "poetic title". It may refer to the myth of Acis and Galatea.

Later botanists did not accept the distinction between Leucojum and Acis. The genus was reinstated in 2004, after it was determined on morphological and molecular grounds that the two genera were distinct.

ACIS

The 3D ACIS Modeler (ACIS) is a geometric modeling kernel developed by Spatial Corporation (formerly Spatial Technology), part of Dassault Systemes. ACIS is used by many software developers in industries such as computer-aided design (CAD), computer-aided manufacturing (CAM), computer-aided engineering (CAE), architecture, engineering and construction (AEC), coordinate-measuring machine (CMM), 3D animation, and shipbuilding. ACIS provides software developers and manufacturers the underlying 3D modeling functionality.

ACIS features an open, object-oriented C++ architecture that enables robust, 3D modelling capabilities. ACIS is used to construct applications with hybrid modeling features, since it integrates wireframe model, surface, and solid modeling functionality with both manifold and non-manifold topology, and a rich set of geometric operations.

History

As a geometric kernel, ACIS is a second generation system, coming after the first generation Romulus

There are several versions about what the word ACIS actually stands for, or whether it is an acronym at all. The most popular version is that ACIS stands for Alan, Charles, Ian's System (Alan Grayer, Charles Lang and Ian Braid as part of Three-Space Ltd.), or Alan, Charles, Ian and Spatial (as the system was later on sold to Spatial Technology, now Spatial Corp). However, when asked, the creators of ACIS would simply suggest that its name was derived from Greek mythology (See also Acis).