Hill disappear when camea up the apparent horizon , why ?

zhucde

24-03-2010 15:21:19

i use the ETM2.3 to deform a hill,

when look up and the apparent horizon below the camera view, the hill disappeard, what's wrong?

Normal:
[attachment=1]11.jpg[/attachment]

look up, when apparent horizon out of view, the hill also disappear:
[attachment=0]22.jpg[/attachment]