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  • Graphic Effects: MIPmapping

    What is MIPmapping?

    A MIP mapping is a type of graphics effects filter that is used to create an semblance of depth in computer design environment. It makes a two-dimensional (2D) samples of a three-dimensional (3D) graphic surrounding. MIPmapping id being used with texture displaying, more of that MIP mapping features multiple visualizations of a each graphic texture map made in different resolutions to show surface textures with an illusion of distances from the user point of view. It simply creates the largest available scaled image and placing it inside the front environment and dynamically placing smaller ones that reaches the farther zones of background area to the same horizon - it depends what level of mip mapping your software/game provides. Every generated image is scaled to feel the difference between what’s close and what is farther - is defined as a MIP map level - higher level means more generated images that builds 3d environment. When the level of MIP mapping is higher, your card performance will be decreased. Besides generating 3D graphics MIP mapping is useful avoiding unwanted scratched edges, these “ragged” borders is called jaggies. Generally speaking mipmapping upgrades the quality level of graphics surroundings by placing various versions of the texture that are minimized more when the 3D depth increases. This graduation of every single mipmap level is dependent on the Texture LOD (Level Of Detail).

    MIPmapping example image

    MIPmapping and 3d environment

    But 3d artificial environment takes more than just MIP mapping to get a proper result, that’s because the texture’s perspective is oriented closer when it gets to the horizon. Therefore the minimized textures are the farther ones from the viewer. The true is that without any graphic filtering of the texture, you can get only a very pixilated image - it is called point sampling. There is a significant rule saying that when the distance from the viewer is increasing, the pixels that are available near the horizontal ones only for representation, that is because the 3d environment runs from the lower zones of the screen to the center.

    mip mapping in-game example

    Take a look at the Mip mapping example above. The left part is done without mipmapping. You might think that it looks sharper in the screenshot here. It is, but without mipmaps all textures flicker with a large amount of noise - this looks awful when the scene is set in motion. Simplifying the Mipmaps are different versions of one and the same texture that is available in various sizes to fit it in a proper place (depth) inside 3D graphic environment. Just try to imagine that you are standing in a long highway and you are focusing on the road texture beginning from your legs to the all way to the same horizon. To secure as much realistic appearance as it possible. The middle lines on our highway which are closer to the viewer must be generated in high details, higher resolution. If you are moving your sight closer to the horizon, the textures gets smaller and smaller. There are situations where details which are closer can be lost due to scaling problem because your graphic card driver doesn’t know which are the most significant details in the texture - it can be avoided by installing a newer driver or lower the level of MIP mapping.

  • Graphic effects: What Is Anisotropic Filtering?

    General

    Anisotropic filtering (AF) is a graphic algorithm of improving the surface texture of an object. Where anti-aliasing is a method of making the edges of an object smoother, the anisotropic filtering is a method of enhancing the way how the objects looks inside, it concerns to all spaces between the edges. Every 3D objects that are used to build a game environment are textured. Texture is no more than a “coat of paint” that covers all those flat polygons to make them look like skin, wood, metal or bricks in the wall. Anisotropic filtering is a technology that became an standard effect in graphics cards in the early 90’s. Now the anisotropic filtering is widely used in graphics hardware.

    Types of anisotropic filtering(AF)

    There are three types of anisotropic filtering (AF). We can differentiate three methods of AF - bi-linear, tri-linear and full anisotropic. The anisotropic filtering is very powerful method, but it also uses lots of GPU performance. Settings that are available for anisotropic filtering are from 2x to 16x. When the level of anisotropic filtering is higher it provides more clear and sharp texture details, but it effects with more GPU usage. Modern nVidia graphic card such as Geforce 285 or even older models like Geforce 8800 handles 16x anizotropic filtering in resolution 1280 x 900 with no problem. For Geforce 285 even 1680 x 1050 is not a challenge, that because of use higher-quality AF algorithm. You can feel the difference between Anizotropic Filtering ON and OFF. Just take a look how anizotropic filtering looks like in action. These examples are a screenshots from 3DMark06 - the graphic benchmark tool. You can open those examples in a new window or tab, switching between them you can see the true difference.

    3DMark06 Anisotropic Filtering (AF) OFF:

    nvidia anisotropic filtering
    (Click this image to open it in new tab to see the difference)

    3DMark06 Anisotropic Filtering (AF) ON:

    nvidia anisotropic filtering on
    (Click this image to open it in new tab to see the difference)

    In short, anisotropic filtering is used when the generated textures are away from the viewer. It gives a smoother border between High resolution textures close to the viewer and lower resolution textures which are used away from “your eyes”. It is very useful for the textures in games with the far horizon. Of Course the textures resolution decreases looking further.

    Anisotropic filtering vs. graphic cards performance

    Anisotropic filtering can have an effect on games performance, even more when it’s used together with Anti Aliasing (AA). Companies building graphic cards such as nVidia are developing this filtering method to gain the best performance. To speed up AF, Nvidia specialists have initiated a special algorithms that makes Anizotropic Filtering calculations faster. Unfortunately it effects the lower amount of AF varies depending on the angle of the surface. The newest cards from nVidia use a higher-quality AF algorithm that have no problem with it but it results in a more round pattern.

  • Graphic effects: What is Anti-Aliasing?

    Full Screen Anti-Aliasing (FSAA) or simply Antialiasing (AA) is a method which reduces the effects of aliasing. You wonder what the Aliasing is? It is simply the jaggedness and pixelation of computer images. It is particularly seeable on things like the straight edges of objects, or the outline of walls or ground in 3D games. These sharp jagged edges can even produce a “sparkle” effect somewhat when you are moving around in a 3D environment. When AA is enabled, it uses your graphics card’s hardware to blend the edges of the jagged lines and hence produce a smoother image.

    Aliasing:

    Aliasing

    Anti-Aliasing (AA):

    Anti-Aliasing

    Anti-Aliasing can have a different multiplicators, usually in steps of 2x, 4x, 6x and 8x. If it’s used the higher is the level of Antialiasing, the image is dynamically smoothed, but it laso uses much more graphics card resource. GPU need more strain processors to recalculate the graphic to produce these smoother images. Also, the higher the level of AA the greater the blurriness you can see. It is sometime a disadvantage because you game or image could become too “cartoon smooth” in appearance, which is not always the ideal effect.