How to get points on screen of objects when using Fisheye camera?

I'm developing a system in which I can get the 2D positions of objects in world space on screen. When I using a normal camera, I can get the correct points on screen successfully via RectTransformUtility.WorldToScreenPoint. However, if I use Fisheye camera (Fisheye shader in Unity's Standard Assets), the screen points computed by WorldToScreenPoint are still the same with the points computed from a normal camera. Is there any method to get points on screen of objects when using Fisheye camera?