By hooking endscene you would be making a d3d aimbot, if you are referring to my sourcecode I hooked the drawframe or whatever. It was an engine function that redraws everything every step. The reason I hooked it is because if I called the function to get the position of entities in my thread it would crash because something else is calling it at the same time. Where as if it was called from the thread that does the endframe function then it wouldn't crash.
So really you don't need any hooks if you are making and engine aimbot, sometimes. In my case I did need a hook and HD helped me make that.
~lilneo