Thanks again for looking into this.
Actually that´s what I did, before I started this research project: I loaded all the skins with the skin manager in MED, the mipmap checkbox was checked by default, and I expected the mipmaps to show up in the engine. For normal models this works fine, but I tested this with different terrains and texture formats (512*512, .tga and DDS with internal mipmaps) but only the first terrain texture (the second skin) was using the mipmaps. The textures that are used for the red and green parts of the RGB map appeared too sharp (pixelig) in the distance.

Actually I would prefer the more simple way, it would be also much more flexible, but I have no idea, why the mipmaps don´t show up.
Maybe I should try the .bmp format? Or maybe I missed something, when creating the mipmaps? Any ideas are welcome ...

PS: I use A 6.50.2 and a Radeon X850XT videocard