It is readily apparent if you go to the top of the Tower Antenna at Pleiku Airbase [16116.6,7373.01,27.1457] and look at any of the hootches, but you can also see this with the hospital and hut (land_vn_quonset), and perhaps other buildings too. It can also be reproduced by placing these same objects in the VR map at different distances and observing them, as in the above screenshot.