Yeh, Jan, Richard, that's good advice. In fact I began experimenting with a negative crater last night, using surface layers for altitude control of displacements on the crater/hump. I've never attempted a generated heightfield that tight before, Inky, but I'm sure your right as its being an alternative method. Yes, Richard, that's probably a weakness of mine; embellishing scenes with figures/creatures. However, (getting defensive now) I do think the camels fit the scene in this case as they readily idetify that straight strip of left to right sand as an ancient trade route, and therefore give the scene a historical/cultural perspective. [Nearly set my bullshit alarm off there].
John.