OldUnreal (Engine)

Flaming Pear Software has a set of free Plugins, most noticable the Solidify A-C plugins, which allow to fill in removed areas of the texture based on transparency. This is in particular helpful, to fill in unused (often black) areas on textures with matching colors, so high mip levels and/or anisotropic filtering won't filter in the black area, but instead a closer matching color and thus mitigating this effect.

http://flamingpear.com/free-trials.html#freebies