Texture Filtering
Reading time: 1 mins.Texture Filtering: Aliasing, Anti-Aliasing, Filters and Mip-Maps
WIP
XX Without filtering, the result looks much more like an image from the original DOOM video game, because without filtering, if you imagine a section of geometry that is very, very close to the camera, several pixels on the screen will cover a single texel of the texture. In texture mapping, to distinguish between the pixels on the screen and the pixels in the texture, we refer to the texture's pixels as texels. So, the projection of a texel onto the screen can cover multiple pixels of the image. When this happens, the result appears very blocky. However, if you use filtering techniques, you’ll achieve a much smoother transition between the different texels of the texture.
XX We can also add that on the GPU, image filtering is done in hardware, making it extremely fast. Linear interpolation itself isn't particularly slow, but the more pixels involved in the filtering process—for example, when using bilinear or trilinear filtering—the longer the filtering operation can take. Therefore, having this accelerated on the GPU is a significant advantage. In essence, texture filtering on the GPU is almost "free."