That seems pretty good, so you can see how your changes effect the....effect....without having to relaunch it all the time. I would guess that you could link this to a image reader that maps the picture (above) from top left to bottom right and uses the alpha to calculate where to place the grass models....

i.e the models that the waving grass is attached too, is deployed according to the image...... The main problem I can see is the z position, i.e do the grass models have a -z until hit something, to place them on the terrain, of can you compare x,y position from the image with the z position of the terrain...and use them to deploy the grass/shrubb models?

I am sure I could get this to work, and may do so yet, but with my current work load it is likely to take some time....

This sounds like a job for the V man....