Test 5

Geezer,

Regarding test image #5. I like the way the bridge looks. The ditch or canal is very natural looking.

How were you able to modify the terrain?

That is a test tile in 3dsMax.  I first made a plane 500m x 500m, then applied the art.  Then, I Tessellated the plane which divided it into many smaller polygons, with points at the intersections.  I then selected those points that sorta/kinda matched the gully and moved the points downward to form a kind of V channel in the plane.

That is the quick and dirty way to roughly simulate a gully.  A better way would require more points, which would enable you to make a floor to the gully with slanted sidewalls.