Why can't I change anisotropic level in a 2D sprite's import settings?

As you can see in the attached image, the aniso level option in the import settings for a sprite I imported is greyed out. I believe this has something to do with a change in a recent Unity update, because I don’t remember aniso level being there before, and all the other sprites which were there before I updated Unity all have it set at 16 (although they also have it greyed out). How could I “unlock” the option? I tried changing the anisotropic-related options in Quality Settings but nothing seems to work.

Aniso Level is greyed out on any type of texture that has Generate Mip Maps disabled.

Mip Maps are useful for improving visual quality and reducing GPU cache, even on unscaled camera-facing 2d sprites, if your game supports multiple screen resolutions. You usually won’t need aniso on these (exception: stretched sprites eg 9-slice boxes).

Anisotropic Textures can be disabled or forced on globally via project quality settings. Both aniso level 1 (the default) and 0 mean “off” but aniso level 0 overrides the “Forced On” global setting and continues to stay “off”. This can have a big effect on performance.

Why would you need anisotropic filtering on a sprite? That seems like an oxymoron to me.

  • Sprites, by definition, are 2d textures aligned to the camera view.
  • Anisotropy, by definition, relates to textures at an oblique angle to the camera view.

I can’t think why they’d ever relate to each other.

I have the same problem, textures that I newly import look very pixeley and the only difference to my old textures is the Aniso Level, which I can’t change as it is greyed out.
My old textures have it set to 16, and they look great. I tried to lower the old textures Aniso level to 1, to find out if they would look pixely like the new sprite (from the newly imported texture), but everytime I press Apply, the Aniso Level on them gets changed back to 16.
Any suggestions?

PS: Please answer the question, don’t give smart-ass answers like tanoshimi here…