For the last of this 3 part series, we’ll build on part 2 by making our trees (or anything else) look at the camera-by rotating those trees in only the Z axis.
This method works equally well for trees or any other object you want to have face the camera (or another object), but only pivot on the Z axis. For example, you can buy collections of photographs (with alphas) of people. You would always want the camera to be facing the flat part of any image, but with people or trees you only want those low poly objects to rotate about the vertical, or Z, axis.