1.Begin by making sure the very bottom of the tree in the 2D texture for the 2D object is the very bottom of the source picture 2.Select all your 2D objects, (make sure they are not grouped)then go to align, (world space option, not object space) then "snap all objects to ground" 3.After thats done, and once you have all your 2D trees made and roughly and positioned in your scene, make sure they are all way above the uppermost points of all your terrains, again make sure they are not grouped, then go to align, "snap to land" 4.If you have "anchor based alignment" turned on, turn it off, or, vice versa, Im not sure. This works for me in Bryce4, I hope it helps.