So how many levels is considered a "full" set?As many levels as it takes to get all the way down to 1x1.
Mipmaps DO go all the way down to 1x1, but I don't understand why. Maybe it's just so the GPU can use that pixel if it only needs to fill a single pixel instead of calculating which of the 4 pixels in a texel is best (or which to blend)? I was under the impression that the smallest texture unit the GPU processes is the texel (a group of 2x2 pixels) and I thought that's why textures always need to be a power of 2 (2x2x 8x8, 4x16, 512x2048, etc)
Anyway, example given, let's say your texture is 512x512 : a full set of mips will look like this: 256x256, 128x128, 64x64, 32x32, 16x16, 8x8, 4x4, 2x2, 1x1 (i guess) so at 512x512, you get a maximum of 9 mipmap levels. In that case, a full set is 9 mips.
Now would someone please clarify the texel thing for me, or did I already guess it?