How to get a bounding box of a staticmesh in final rendered image

Hi, guys!
I want to get the accurate 2D bounding box in final rendered image like this.

But according to my knowledge, there isn’t any API in UE4 to realize this directly. I know there is an function GetBox() return aabb bounding box. I have tried to transform the aabb bounding box position to the image coordinate, and compute the the min and max positions of the aabb bounding box in the rendered image, but it is not accurate enough. Does anybody have any idea about this issue? Thanks for any advise.

Bumping this since I also would like to know.