Let me see if I get this straight. You want to create 1 scene file with all the action as if you are on the set of a movie (ie like in real life) and then be able to move the camera around taking "pictures"/renders. a) depends on the specs of your machine (mostly how much RAM it has) b) There are trees made of 2D planes in the objects presets (or content disks if you have them). A flat 2D plane/object will only work if looking straight at it and thus you won't be able to just move the camera around. c) You will almost literally have to create a small world for what you want to do which will require several terrains (what ricky suggested will only raise the res of the terrains to unneccessary proportions and drag your comp down (ie huge amounts of unneeded polygons). You can edit the terrain size in the edit pallette and make it real big (sculpting it in the terrain editor to the shape you want) and use this as the base terrain then add other terrains for detail and low res terrains for background.