well yes, as is also the vegetation grass, but other vegetation types are for example painted , it really depends what comes out best , the palm trees in crysis 1 where most probably handpainted while ther trunk was photosourced and reworked .
Oh well , when I made my own palms I tried to "copy" the techniques used by them in cryengine 2 but I have handpainted them , it was long and tedious work but that was the result ... Picture now some other things where taken from photoes like wood , but then I had manually edited a lot , the sand instead was just noise and…