Hi, as you can see in the image, i’ve some issue with the custom depth and this outline function. The problem is that i have no idea of how i can mask out the outline effect from any mesh in front and behind. For example, near the head i should no see the outline, same thing with the rear faces (crate hided by crates). How i can do? Thanks
bump 
Anyone can helps please?
check this blog out, maybe it can help
Thanks,
Hi Kheka,
Have you fixed your issue yet?
I had what I believe is the exact same problem: Custom depth buffer causing objects to draw in front of other objects - Rendering - Unreal Engine Forums
Which I think I have now fixed. If you can post a screenshot of your post process material, I can see if my solution is relevant to your issue.
So I am having this same issue but am very new to UE4 material editor. I do have some rendering experience and know what is causing and how to fix this issue but I do not know how to execute it. Within the shader where you are sampling the custom depth, you need to compare the custom depth value with the depth of the main depth buffer. By doing so, you can determine if an object is overlaying the outline or not and if so, not to render the outline at the given pixel. This should work and I am currently playing around to do just that. If I am successful, I will get back to you. =D