News -

Some of the 'Latest Graphics Systems & Graphics Boards' as of Jan 2004

Received From: #WANG SHING CHAI#            Sent: Tue 2/3/2004 1:41 AM
graphics card specifications   ATI Radeon 9800 Pro 256Mb DDR2

From: #PONG YUAN SU#                                    Sent: Mon 2/2/2004 10:35 PM
From: Chong Ming Ng                                             Sent: Mon 2/2/2004 8:40 PM

Fastest graphics subsystem specifications
http://www.ati.com/products/radeon9800/radeon9800pro/specs.html

From: #TOH TZE MENG#                                    Sent: Mon 2/2/2004 8:16 PM
VGI AMD FX-51 Graphics System based on Nvidia Quadro 4 750XGL DDR Graphic Card
http://www.vgicomputers.com/prebuilt-current/graphic-station-Athlon.htm

From: #SEAH KIAN KAI#                                    Sent: Sun 2/1/2004 7:11 PM
Complete graphics system  Intel Xeon Processor & Quadro FX 500 PNY

From: #CHAN WANG YIP#                                                        Sent: Sun 2/1/2004 2:47 PM
ATI named FireGL X2-256T
Silicon Graphic workstation. Onyx4 UltimateVision
QuadroFX manufactured by NVIDIA

From: #KWAN WEI PIN#                                                            Sent: Fri 1/30/2004 2:25 AM
Hercules Graphics Card

From: #KOH FUQUAN,ALEX#                                                    Sent: Thu 1/29/2004 4:30 PM
This is the link to a page comparing graphics systems/cards from 3Dlabs, ATI and NVIDIA.
http://www.3dlabs.com/product/technology/wildcat_quality.htm
According to 3Dlabs, they have the best graphics system/card in the world at the moment.

From: #LIM FEI HUANG#                                    Sent: Wed 1/28/2004 11:45 PM
1. ATI 9800XT
2. GeForce FX5950 Ultra

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Received  Patrick Thun 8/17/01 11:15 PM 

"When do we use 1,2,3 point perspective?"
The answer to this question can be found from the following link. http://mane.mech.virginia.edu/~engr160/Graphics/Perspective.html

In short, One-point perspective occurs when the projection plane is parallel to two principal axes.
A two-point perspective projection occurs when the projection plane is parallel to one of the principal axes or when the projection plane intersects exactly two principal axes.
Finally, if the projection plane is not parallel to any principal axis, a three-point projection occurs with the visual rays converging to three vanishing points.

Received  #TANG LI KOON#   8/20/01 12:18 PM

"When do we use 1,2,3 point perspective?"

A One-Point Perspective
It is used almost exclusively for interior-room views. It gives the observer the illusion of looking into the room.
Hence one point perspective is used when we want to have a direct straight view towards the object.

Two-Point Perspective.
It is often used for architectural renderings. With the two-point perspective the visual rays converge at either the left or right vanishing points.

Hence two point perspective is used when we wish to display an object where its front and two sides can be seen. This also allows
us to put measurements on the object more easily.

Three-Point Perspective.
If the projection plane is not parallel to any principal axis, a three-point projection occurs with the visual rays converging to three vanishing points. Hence we use three point projection when the projection plane is not parallel to any principal axis.

 

Received  #TAN CHIN KIANG#  8/20/01 12:44 PM

The following are the uses of single, two and three-point perspective projections as requested.

Single-point Perspective Projection:
One-point perspective occurs when the projection plane is parallel to two principal axes. When the projection plane is perpendicular to one of the principal axis, one point perspective occurs. Receding lines along one of the principal axis converge to a vanishing point. A one-point perspective is most often used for interior-room views where a person will only be looking from one side of the drawing.

Two-point Perspective Projection:
Two Point Perspective is a more useful drawing system for mechanical or architectural drawing. Objects drawn in two point perspective have a more natural look. In two point perspective the sides of the object vanish to one of two vanishing points on the horizon. Vertical lines in the object have no perspective applied to them. By altering the proximity of the vanishing points to the object, one can make the object look big or small.

Three-point Perspective Projection:
Three point perspective is a development of two point perspective. Like two-point perspective, it has two vanishing points somewhere on the horizon. But three point perspective also has a vanishing point somewhere above or below the horizon which the vertical vanish to. The nearer this vanishing point is to the object, the bigger the object looks. In general most designers create drawings with a vanishing point far below the horizon so that the depth added to the verticals is only slight. In many cases the vanishing point isn't even on the paper. Correct application of the vertical perspective can actually make drawings more realistic.

Received  Low Keng Hong 8/22/01 6:05 PM 
Received  #WONG PUAY KIT#   8/21/01 2:05 PM 

Question:When do we use 1 ,2 ,3 vanishing points in graphics ?

1 vanishing point is used when demonstrating that something is lies far away. Example the racing track
in a computer game. The track is drawn in such a way so that the track converges in one point, thus making
an impression that the track lies far away.

When 2 vanishing point is used, the sides of the object vanish to one of two vanishing points on the
horizon. Vertical lines in the object have no perspective applied to them.

One usage is for example when we are looking at a corner of a building having 2 streets perpendicular to
each other. The 2 streets vanish at far left and right ends.

3 vanishing point is an extension of two point perspective. Like two point it has two vanishing
points somewhere on the horizon. But three point perspective also has a vanishing point somewhere above
or below the horizon which the vertical vanish to.

One usuage is when we try to illustrate that the object that we are looking is very high above a plane.
For example, when we are looking above the object and at 45 degrees from y-axis. When the object move
towards the ground, it become smaller and when the object moves upwards and toward me. It magnifies.


Received  8/22/01 3:25 PM    Tan Tse Chau, Henry

*************************************************************
Question: When do we use 1, 2, or 3 point perspective??

************************ Solution ***************************

There are a few things about perspective:

Perspective in reality involves a gradual re-sizing of objects at increasing distances. Therefore, an object passing through varying distances away from the camera will be subject to that gradual perspective.

All perspective lines radiate from their singular points. In addition, lines that are in reality parallel with each must all come from one source .

1-Point Perspective:

When an image shows a view that apears to be looking directly at a single main vainishing point, the scene is a one-point perspective. This is the case when looking down a tunnel, looking straight up at a skyscraper, or looking directly down at rooftops of a city. It can be used to focus attention at the place where the lines converge. It can also be used to try to draw the viewer in. With a one-point perspective drawing elements seem to be aimed at the viewer, or passing by on all sides.

The one-point perspective gives the viewer the sensation of being led by the nose -- forced to look at something in a way that is not of the viewer's choosing. Used inappropriately, the one-point perspective can be boring. For example, you probably wouldn't want a one-point perspective looking directly at a wall. Generally speaking, a wall is a rather static thing to be looking at.

In another view, you might feel that a particular one-point perspective is exciting, or is the logical way to look at something. Or you might choose a one-point perspective for a particular work precisely because it make the viewer feel trapped, or because it feels static.

2-Point Perspective:

The two-point perspective is a much more common type of drawing. The view can be of a scene outside, where buildings or other elements vanish towards the horizon. Or it can be an interior scene, where walls or other elements seem to wrap around the viewer. Usually in a two-point perspective, the viewer is looking in a direction approximately parallel to the ground, so vertical lines do not converge with each other. The image is such a drawing. Nothing is being thrown directly at the viewer, and the viewer is not looking directly at a single wall or down a passage; instead the scene opens in a couple directions. The most noticeable objects are seen obliquely, rather than axially. This type of drawing tends to provide a sort of stage for the characters of the drawing, where the viewer's attention is not directed a forcefully toward a single point.

Usually, a two-point perspective has a left vanishing point, and a right vanishing point. On rarer occasions, a two-point perspective is of a different sort, where there is an upper vanishing point and a lower one. You might do this if you wanted to give the viewer the impression of walking down some sort of axis, but of looking somewhat up or down, instead of parallel with the ground. Lines parallel with the axis converge toward a point on the horizon, but vertical lines also converge. Height is emphasized.

3-Point Perspective

Three point perspectives are more complicated to draw, and are rarer, since they typically involve the viewer looking up or down at a scene instead of horizontally at it. You might use a three-point perspective in a situation where you want a broad stage and an emphasis of the vertical dimension .You might also use a three-point perspective in a situation where you are trying to make every direction seem equivalent, such as in outer space drawing below, where the drawing was supposed to give the impression that there was no "up" direction.


Received: 8/23/01 11:42 PM  Viona

There are also multi-point perspectives where the number of vanishing points used is equivalent to the points of convergence. They are used to draw roads, cities or country-scapes.





Received  8/24/01 2:05 AM  Mohammad Nazri

Use of vanishing points

The number of vanishing points in a projection is determined by the number of principal axes intersecting the view plane.
Eg. For a cube centered at the origin :
One vanishing pt: The view plane is aligned to the xy object plane so that the object z axis is intersected.
 
Two vanishing pt: An x-axis and a z-axis vanishing point can be used such that the projection plane intersects both the x and z axes but not the y axis.

 

15 Aug 2000
Graphics Systems Specifications:- from Herry Soeprapto 
Intel Pentium III 866MHz processor with 133MHz FSB ans system architecture based
 on Intel 840 chipset
256MB ECC RDRAM expandable to 1GB
10,000rpm Ultra160 SCSI harddisk drive with Ultra160 SCSI controller on-board
Graphic Cards 3DLabs Oxygen GVX1 AGP2x OpenGL with 32MB memory
HP PCI 10/100 Base-T Ethernet adapter with LAN Remote Power On/Off
HP 4x Max-speed internal IDE CD-Writer Plus Drive
 

Whenever the term “Graphics System” is mentioned, the first thing that comes to the mind is the computer monitor. This because the monitor screen is one of the most essential elements of a computer system. Other peripherals that can be part of the graphics system include printers, plotters, scanners and also the colour LCD panels which seems set to replace the colour monitors in the near future. In this write-up, we will investigate the features and some general specifications of a colour monitor.

Monitors
Monitors come in a dizzying array of sizes, capability, and prices. To simplify the discussion, we will stick to VGA monitors and better. Many older generation PCs were shipped with VGA (not SVGA) monitors are not capable of displaying higher resolutions even with a more expensive video adapter. Monitors that display VGA resolution only and "paper white" VGA monitors are no longer sold and are rarely worth repairing.

Screen Size.
Monitors, like television sets, are measured diagonally, from two opposing corners of the picture tube. The standard monitor size is 14," and prices rise rapidly with increasing screen size. Very large monitors can measure 21" diagonal or greater and weigh over 80 pounds. Manufacturers of monitors, like manufacturers of some clothing items, are not entirely consistent with their measuring schemes. Some measure parts of the picture tube that are hidden behind the plastic bezel of the monitors casing, and others simply don't allow the screen size to be adjusted to anywhere near the edges of the bezel. This has led to an unofficial measurement known as "viewable area," measured diagonally, which describes how large a picture you can actually see. For example, one 17" monitor may have a viewable area of 16 1/2," while another may have a viewable area of 15 1/2." One recent innovation is the "flat screen" monitor, which doesn't have the curved face of the standard picture tubes in most monitors and televisions. Flat screens look a little better than standard monitors and cost a little more.

Interlace and Horizontal Frequency
The two factors that control how "solid" or "flicker free" your monitor is are the whether or not the display is "interlaced" or "non-interlaced," and the horizontal frequency, which controls how many times per second the screen is redrawn. Monitors, like televisions and movie projectors, flash a series of pictures at us, which our eyes and brain merge into a solid image. How many images per second are required to create a really "solid" looking picture varies from individual to individual, but the minimum number of times per second (frequency) an image is displayed by any modern monitor is 60 per second (60Hz). The costs of the electronic components that control the picture tube go up in price as they go up in speed. One trick that allowed monitors with slower electronics to draw SVGA resolution images without excessive flicker is "interlacing." When an image is interlaced, the monitor draw the entire image more than 60 times per second, but skipping every other line. On the next redraw, it does only the lines it skipped. The result is that the entire image appears less bright and a little flickery to some people, while others don't notice. A non-interlaced (NI) monitor will be capable of drawing the whole image every cycle. Interestingly, most clone builders never bothered properly configuring the software and the video adapter to work with the NI monitors, thus buyers didn't get the benefit they paid for.

Even with a NI monitor, some people who stare at monitors all day long, especially under artificial lighting, see flickering or get dizzy by the end of the day. The way to make the picture appear even more "solid" is to run up the horizontal frequency to 72Hz or 75Hz. The increase in price to the video adapter is trivial, in fact most 512K and 1MB SVGA adapters can already handle 72Hz, known as the VESA frequency (VESA for the Video Electronics Standards Association). The real challenge for both adapters and monitors is maintaining the higher horizontal frequency at screen resolutions beyond SVGA. Why does it matter? Well, for a VGA screen, the monitor electronics must draw 400 lines each 640 pixels long during each cycle. For each pixel in each line, the video adapter must tell the monitor how much of each primary colour, red, green and blue, to light up for each pixel. At SVGA resolution, 300 lines each 800 pixels long must be drawn in interlaced mode, and 600 lines of the same length in noninterlaced mode.

Resolution and Dot Pitch (DP)
How "sharp" an image looks is determined by how many pixels (dots) the image is made comprises, and how large the dots are. The best combination to create a really sharp image is a high resolution with a low dot pitch (DP). Resolution depends on the video adapter, software and monitor all working together; the dot pitch depends on the monitor alone. Manufacturers use a couple of different approaches to defining dot pitch, but it basically defines how large each pixel or dot on the screen ends up being. Fourteen inch monitors should have a .28 DP, while larger monitors range from DPs of .25 to .31. A 14" monitor with a high dot pitch, say .39, is cheaper, but image definition is poor. The trade off on resolution is a given image displayed at two different resolutions will appear sharper at the higher resolution, but larger at the lower resolution. Most people run their 14" SVGA monitors at VGA resolution for this reason, although it's nice being able to switch to a higher resolution when you need to. If you want easily readable screen fonts (characters) at SVGA resolution, consider a 17" monitor.
 
 

28 July 2000
Some tips on how to create better images!

For a template file <Click Here>

There is one page on how to compile Opengl in VC at
http://devcentral.iftech.com/learning/tutorials/mfc-win32/opengl/2.asp
However this require using the MFC, which can be difficult to port to Unix.