Wikipedia:Portal:Portal
 | This page contains material that is kept because it is considered humorous. Such material is not meant to be taken seriously. |
The portal of portals
A portal is an opening in the walls of a building, gate or fortification, and especially a grand entrance to an important structure. Doors, metal gates or portcullis in the opening can be used to control entry or exit. The surface surrounding the opening may be made of simple building materials or decorated with ornamentation. Elements of a portal can include the voussoir, tympanum, an ornamented mullion or trumeau between doors, and columns with carvings of saints in the westwork of a church.
Portals in science fiction, such as wormholes and gates, allow rapid travel between distant locations, often originating from some combination of natural phenomenon and technological device. These fictional devices are required for most stories on an inter-solar scale, otherwise transit time would be excessive for storytelling purposes. An advantage of portal technology over a faster-than-light drive is that it can be imagined to work instantly, and can travel to the past or future. In other forms of fiction, a portal may be magical, and connect to an alternate universe or plane of existence.
Selected article
In computer-generated imagery and real-time 3D computer graphics, portal rendering is an algorithm for visibility determination.
A game level might contain many graphical polygons; only a few of which may be visible on screen at a given time. Visibility determination allows the renderer to decide which of those fall into that category and thus reduce rendering time.
For example, in a computer game, the game area might be divided to several sectors. These sectors would be then connected to each other by small openings such as doors or windows. These openings are referred as portals. When the sector behind a portal needs to be drawn, the only parts that are visible are the parts that can be seen through the portal. Therefore, the sector can be clipped against the portal boundaries to remove overdraw.
The use of portals simplifies the game engine's task of determining visible areas and objects from any given point of view of the level, and simplifies rendering by allowing it to use each portal as a viewing frustum for the area it leads to.
Selected biography
Baron Antoine Portal (January 5, 1742-July 23, 1832) was a French anatomist, doctor, medical historian and founding president of the Académie Nationale de Médecine. Born in Gaillac, he was the eldest among 12 siblings. He studied medicine in Albi, Toulouse and Montpellier and started his career as a teacher of anatomy.
In 1766, Portal moved to Paris to take up a similar post, and was appointed to the prestigious position of professor of anatomy to the Jardin du Roi. Louis XVIII named him the first Doctor to the King, a post he also served in under Charles X. His close relationship with King Louis led in 1820 to the creation of what became the Académie Nationale de Médecine, of which he was lifelong president.
In 1803 Portal published "Cours d'anatomie médicale", a 5-volume work on medical history. He was probably the first to describe amyloid in liver in 1789 when he noted a lard-like substance in an elderly woman's liver, and the first to describe bleeding due to esophageal varices. He also published article on clinical features of epilepsy.
Portal died in 1832 at the age of 90 and was buried in Saint Pierre de Montmartre.
In the news
- Door opens mid-Qantas flight; plane makes an emergency landing
- Belgian Indymedians discuss participatory journalism at open door day
- Alaskan plane crash survivors say cargo door swung open
- World Health Organization launches clinical trial website
- Kids game portal BBC Jam to close after competition complaints
- With pressure from France, Chad and Sudan open door to possible troop deployment
- Switzerland shut door on Korean Republic 2-0 in Group G
- Sydney train doors stuck, passengers delayed
- Entrepreneur's RFID chip implant to open doors, start car
Categories
- Doors — panels or barriers used to cover an opening
- Gates — entry points to an enclosed space
- Portals — focus pages which highlight a particular subject
- Portals on Wikimedia Commons - images of portals
Did you know?
- Portal hypertension is often the result of cirrhosis of the liver
- The Dark Portal is the first book in the Deptford Mice trilogy
- Fort Portal in Uganda is the seat of both Kabarole and the Toro Kingdom
- Portal's Weighted Companion Cube has fan-created plush and papercraft versions
Selected picture
Selected geography
Portal is a city in Burke County, North Dakota in the United States. The population was 131 at the 2000 census. Portal was founded in 1893.
Portal sits near the Canadian border and is a major port of entry for road and rail traffic. It is one of three 24-hour ports in North Dakota (the others being Dunseith and Pembina). The town is known for its "international" golf course. The ninth hole is partially in the United States and partially in Canada.
Selected quote
From the depths of the gloom wherein you dwell, you do not see
much more distinctly than we the radiant and distant portals of Eden.
Only, the priests are mistaken. These holy portals are before and not behind us.
- — Victor Hugo, letter to the Italian translator of Les Misérables
Related portals
