Sorry im not quite often here, and im quite busy all the time, in addition to my lack of a constant webacces.
I used Max for years, however i didn't touch it since a year or so, instead using Maya for my projects.
But i want to give some idea for this little problem:
I had this problem in maya once and solved using a simple MEL script. Of course this will not work directly but the principle is working everywhere.placing all this grass hmmm,is there a way to make the static models conform to the terrain,or do we have to manually move the seperate pieces of foliage by hand?
The basic idea is to use particles as placeholder for the vegetation objects (pivots), and then use collision between particle and surface to place them directly on the surface.
Create a particle emitter that fits the size of the terrain but is above, spawn some, then let them fall directly on the terrain surface, avoid any friction or movement, except for the z-axis (top to down).
All particles should now be on top of the surface, now add for every particle a vegetation object, make sure the pivot point is set correctly.
This can be done in Max,Maya or even directly in Ca3D if Carsten provides a proper tool, since particles can collide easily with terrain so far !
This way of scattering could be used for many other situations, or even be more refined for more control (deleting particles, mixing more than one vegetation object, adding random rotation/scale/color values for foliage planes and so on)
just my two cents in breaktime