chris,
excellent tut for another way of achieving depth in terrains.
in july, i had similar doubts and was helped by kris, gai and tom. unfortunately that thread is lost now but i can still quote from the message by tom that i had printed. it refers to the skippy mentioned below. here it goes:
@unknownuser said:
tomsdesk:
on the left of attached is a terrain (grossly exaggerated vertically) with all the edges of curbs and walks intersected (including the extra edges to form the faces that will be "stretched" during the vertical alt-move processes).
to get to the right i first picked all the gray road faces and alt-moved them to 6"...this formed my curbs (which are slightly sloped as is the case with the detail i use here). then i picked all the grass faces (not the skinny strips along the curbs and walks) and alt-moved them up 2"...the skinny strips then formed the vertical faces of the grass (slightly sloped: just like grass)
looking closer to the red circle over the right model you'll see it isn't perfect. SU still assumes in several places i wanted something different than it did for me everywhere else...so there is always a little cleanup to be done.
EDIT: the correct location is http://www.sketchucation.com/forums/scf/sas/ProUser/sitetech.skp
i hope it helps anyone.