Actually it was one of my very first posts in this part of the forum half a year ago. You sure you searched?

As for how to fix it, I remember someone at CA telling me about modifiying several texture files, but that the net result would not actually be very visible in terms of performance. Besides, my lack of graphical skills kind of prevented me from modding those files anyway.

extract files which the word "canopy" inside them with your unpacker. Best the entire folder they are found in (forgot which one, but you'll know after doing the former)