added width,height and depth vars to GameObjects, randomly position 25 trees about the terrain.

lib/objects/tree.rb

@@ -2,6 +2,7 @@ class IMICFPS
   class Tree < GameObject
     def setup
       bind_model(ModelLoader.new(type: :obj, file_path: "objects/tree.obj", game_object: self))
+      self.y = @terrain.height_at(self)
     end
 
     # def update