Well, you are supposed to render out a flipbook of the billboard, so that when you rotate your camera around it, it will load the correct image for the angle at which you are looking at it. It is actually called an "Imposter", You should try rendering a 4x4 flipbook (Squib) with 16 angles of your tree. Then rotate your camera around it. I think you will find it somewhat magical. Assuming of course that is fully integrated.
Hey modman. Thanks for your response.
For some reason i wasn't even thinking that far but you're obviously right. So I set up a camera(orthographic) and lighting rig and created a batch render in 3ds max to render out the flipbook. The assest Y direction is the front and the camera has to rotate clockwise from there. Also the imposter plane has to face in Y direction when exported.
This is the result: (Wished there would have been some documentation though.)