Textures appear as boxes at closeup

In my 3D application, I am processing the keyboard input in such a way that you can 'move' around using arrows.

My problem is, when I get close to the textures applied across the 'walls' they appear as boxes - like if you zoom an image 8x in MS Paint.

The size of the image is 256x256 and the size of the 'wall' in 3D is also 256x256.

How can I stop them from appearing as boxes. What should I do to atleast blur them to some extent so that they appear somewhat smooth?

Well I'm not an expert but I would suggest using... for example 1024x1024px images on your walls. But since that's rather large I would suggest using the texture size you use now but scale down your world about 4 times. I hope this helps.

Well, actually I think the answer is related to Filtering levels.

After a (very) long time spent on searching the web and forums I finally found the answer. We have to set the filtering levels to some ANISOTROPIC level or something.

I haven't figured out everyting yet, but I think I'll do some research on that.

Anyway, thanks for stopping by!