![]() ![]() In order to save on transistors and to improve on the locality of data, they are organized in Quads or even Octs, putting out four or even eight textured pixels at a time. Modern TMUs are capable of fetching the necessary values and averaging them almost instantaneously, achieving a throughput of one filtered texel per clock. ![]() This is achieved by averaging four square-aligned points inside the texture and is usually handled by a fixed-function block within the graphics processors Texture Mapping (or Management or Memory, if you prefer) Unit, shortened as TMU. Texture filtering removes those blocky artefacts older ones might remember from the glorious days of DOS and the first 3D games. That's the issue I want to shed light on today.Ī little (oversimplified) background on texture filtering ![]() The texture shimmering in this case is clearly due to bad art design on Valve's part, but please direct your attention towards the end of the tunnel - you might see a harsh transition in the level of texture detail in one of the clips, whereas it appears much smoother in the other one. (There are some more videos from this scene in my Youtube channel, also with Geforce cards and optionally supersampling anti aliasing applied) In order to illustrate the point, heres a small 720p-clip taken from Half-Life 2 with my trusty HD 5870, then another one with my HD 4870. Recent Geforce cards do that, and also AMDs own HD4000 series, which were seemingly inferior to the 5k series. Now, there's a small caveat, even if you chose to ignore the texture shimmering issue: Sometimes, and it isn't clear when and why this happens, the Evergreen chips show an abrupt mipmap transition where there should a smooth blending from one mip level into the other. Even though AMDs offerings of late exhibit a more pronounced tendency towards shimmering in fine grainded texture detail, some reviews and reputable magazines declared them ruling kings of image quality - something the fanboys from the red camp really liked and re-trumpeted around the forae of the internet. The approriate screenshot from a little application known as AF-Tester was shown and repeated through most of the reviews in the internet world. Texture attribute interpolation was moved from the TMUs into the shader core and the angle dependency had almost vanished. When AMD launched the HD5000 series, also known by their collective codename Evergreen, they were proudly directing attention to the improved anisotropic filtering, more specifically two things: ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |