terrain smearing?

Not sure if that is the best word to use to describe it but I have a simple terrain project that when initiated and yo begin to move around the upper edge of the back side of the terrain appears to be smearing. If I make the terrain move down in my field of view the horizon stays where it is and the edge keeps getting redrawn as I move the horizon down. Any idea what is causingt this to happen.

My immediate guess would be that you are not clearing the screen at the start of every frame.

Originally posted by mj:
Not sure if that is the best word to use to describe it but I have a simple terrain project that when initiated and yo begin to move around the upper edge of the back side of the terrain appears to be smearing. If I make the terrain move down in my field of view the horizon stays where it is and the edge keeps getting redrawn as I move the horizon down. Any idea what is causingt this to happen.

are you calling glClear() each frame, before drawing your terrain??