   Trees
  ok. I have this 3d world with terrain. and I was wondring how I can add trees to the terrain?   
  Personally i would make a tree mesh in a 3d modeller such as Maya or MilkShape, then export it to the .X format. The load this mesh and perform transforms on it to scale and translate it to fit your terranThen, make an array of them at random locations in the mapRender this array in OnPaint using the DrawSubset() method   