FAQ: Graphics Terminology

[MrAlex]

Graphics Terminology

Ambient Occlusion

 

This is the shading of an object by light due to occlusion. See also: Occlusion, SSAO

 

 

Image source: http://www.renderpix...ent%20Occlusion

 

Analytical Anti-Aliasing (Abbreviation: AAA)

 

This version of anti-aliasing is done using mathematical analysis to avoid jagged lines around an object by covering the lines with another line of pixels.

 

Anisotropic Filtering (Abbreviation: AF)

 

In its simplest form, it is the sharpening of textures to make them appear less blurred. See also: Bilinear, Trilinear Filtering and Mipmaps

 

Anti-Aliasing (Abbreviation: AA)

 

This is a method of ‘smoothing’ jagged edges. The jagged edges are caused because our screen is made up of tiny squares (pixels) that make up the screen. Therefore, circles and other round images are made up of squares, which cause jagged edges. Anti-aliasing helps to smoothen it out to make the image appear more natural. Generally the more smoothing that occurs, the greater the loss of performance. See also: AAA, CSAA, MLAA, MSAA, SSAA

 

 

Bilinear Filtering

 

Sometimes textures are displayed larger or smaller than they are supposed to be. This can make them look pixelated or blurry and so bilinear filtering smoothens out the textures.

 

CrossFireX

 

This is AMD's term for running multiple AMD graphics cards simultaneously to improve performance.

 

Coverage Sampling Anti-Aliasing (Abbreviation: CSAA)

 

This is a more efficient version of MSAA, developed by NVIDIA, which stops the dependency of shaded colours with each other, reducing bandwidth and storage. According to NVIDIA, they claim that it rivals to 8x or 16x MSAA.

 

Floating-Point Operations per Second (Abbreviation: FLOPS)

 

Is the rough measurement of the performance of a processing unit calculating float-point operations.

 

Frames per Second (Abbreviation: FPS)

FPS is an acronym for Frames per Second, which is what it means – how many frames (pictures) displayed every second. The more properties are enabled such as anti-aliasing (the smoothening of edges) and higher detail, the lower the FPS, because the graphics card has to process more data.

 

Graphics Double Data Rare (Abbreviation: GDDR)

 

GDDR is similar to DDR. The main difference between them is that GDDR consumes less power and requires less voltage than DDR, but is more expensive.

 

Graphical Processing Unit (Abbreviation: GPU)

Is an acronym for Graphics Processing Unit, the chip on a graphics card that processes all of the data.

 

Mipmaps

 

This is used in conjunction with anisotropic filtering. It is smaller variations of textures used compared to a bigger one, such as to display on a 3D object for example. When up close to the texture, it will look very sharp and crisp and as you move away it will more so. The problem comes when that texture is far away, but is still being rendered at the original resolution, adds extra strain to the GPU when lots of far-away scenery is being rendered. The solution is to use smaller sized version of the texture to render at further distances – the further away from the object, the smaller the mipmap.

 

Morphological Anti-Aliasing (Abbreviation: MLAA)

 

This type of anti-aliasing involves rendering a whole scene completely and then removing aliasing after with hardware acceleration. So far on PCs only AMD Radeon graphics cards support MLAA. Some PlayStation 3 titles also utilise MLAA, such as God of War 3 and The Saboteur.

 

Multisampling Anti-Aliasing (Abbreviation: MSAA)

 

This is a more efficient improvement of SSAA, due to there being large performance issues as the resolution gets higher, to which MSAA does the same thing as SSAA without the large performance hit.

 

Occlusion

 

In layman’s terms it is the blocking of the view of an object from another object.

 

Pixels

 

Your whole screen is made of pixels – tiny dots that can display up to 3 or 4 different types of colour. Pixel is the short name for picture element. The 3 or 4 colours are red, green, blue (RGB) or cyan, yellow, magenta and black. When we talk about screen resolution, we talk about how many pixels are shown on the screen. For example, 1280x1024 means that there are 1280 pixels from side to side (left to right or vice versa) and 1024 from top to bottom (vertically).

 

Pixel Shader

 

A shader that affects the way a pixel is rendered, such as its colour, depth and the likes. See also: Pixel, Shader

 

Refresh Rate

 

Refresh rate is basically what it sounds like; it is how many times your graphics card re-draws (or ‘refreshes’) the screen. Usually, the higher the refresh rates the better, as the image is clearer and will remove any artifacts or lines. It is measured in Hertz (Hz), so a refresh rate of 75Hz, means the screen is redrawn 75 times in a second.

 

Screen Space Ambient Occlusion (Abbreviation: SSAO)

 

This is simply the use of Ambient Occlusion running in real-time.

 

Shader

 

This is a piece of software that has an effect on the way that things are rendered. See also: Pixel Shader, Vertex Shader

 

Shadows

 

In graphics terms, there are generally two types of shadows that pop-up most often: Hard and Soft shadows. They are what the sound like, a hard shadow is a shadow with sharp edges while a soft shadow is a shadow that is more realistic, with blurred edges.

 

 

Image source: http://artis.imag.fr...rd_vs_soft.html

SLI

 

This is NVIDIA's term for running multiple NVIDIA graphics cards simultaneously to improve performance.

Super Sampling Anti-Aliasing (Abbreviation: SSAA)

 

Put simply, it is the taking of more samples to increase the density of an image.

 

Tearing

 

Tearing occurs when a large number of frames are output, more than the output device can handle, or which does not have its settings properly calibrated – resulting in an overlap of frames. It is generally prevented by using Vertical Synchronisation.

 

 

 

 

 

Image source: http://www.arcadeita...?p=46084#p46084

 

Tesselation

 

Is the use of smaller shapes to make bigger ones, such as two triangles making a square. By itself, tessellation hardly improves anything, but needs to be used in conjunction with a displacement map to give the object depth and perception.

 

Trilinear Filtering

 

Unfortunately, Bilinear Filtering has its weaknesses because when the transition happens between different mipmaps, it can become obvious showing straight lines that separate the different sized textures. The solution to this is trilinear filtering. It ‘smoothens’ out the transition between different mipmaps.

 

Triple Buffering

 

Triple buffering is the simultaneous action of holding triple the amount of temporary data that is moved from one location to another. This is used to attempt to get rid of artefacts, image tearing, flickering and the likes.

 

Vertical Synchronisation

 

Vertical Synchronisation, often abbreviated to VSync is a method that tends to 'lock' the FPS of an application to the Refresh Rate of a monitor. For example, most monitors have a refresh rate of 60Hz and therefore with VSync enabled FPS is locked at 60. This is usually done for higher image quality and to prevent image tearing.

 

Vertex Shader

 

This type of shader affects the vertices of an object, such as its colours, textures and co-ordinates. See also: Pixel Shader, Shader

Edited April 27, 2011 by MrAlex

[Rofltroll]

nice read

[Savan]

looks good. there are probably more errors than this, but in the triple buffer section artifacts is spelled wrong

[Rofltroll]

looks good. there are probably more errors than this, but in the triple buffer section artifacts is spelled wrong

I doubt those are the types of errors he was talking about.

[ir_cow]

pretty good, i would suggest a different sync picture. i know what to look for but other than the piller it would look fine to most. use HL2 for some good screen shots.

[MrAlex]

looks good. there are probably more errors than this, but in the triple buffer section artifacts is spelled wrong

 

Proper British English for the win

[MrAlex]

Bump Anyone got any other terms I should include?

[MrAlex]

[Flibo]

I couldn't really find any important mistakes, but you could mention that refresh rate is how many times something is refreshed in a second in the first sentence of the explanation. Also, 'hertz' is not written with a capital letter (Hz is though).

[MrAlex]

I couldn't really find any important mistakes, but you could mention that refresh rate is how many times something is refreshed in a second in the first sentence of the explanation. Also, 'hertz' is not written with a capital letter (Hz is though).

 

I've already said that. Read the end of the paragraph

[IVIYTH0S]

I didnt see any real obvious issues, good stuff Sir Alex

[SiL3nTKiLL]

good stuff! this should help a bunch of ppl out