Hi son1cman -
There are two options that you can try here. Assuming your mesh is mostly smooth edged (not right angles meeting), you can try a setup like this:
which yields results like this:
As you can see there are issues with the way the outline is applied here which case the top pixels to render in the same depth resulting in the black top.
Alternatively and probably better ultimately for performance and for most accurate outline would be the old method of doing outlines which is to duplicate the mesh, increase the duplicate’s scale by a small outline (thickness of your outline) and invert the face normals.
In this case you would end up with each results very close to the post process method like this:
Thank You
Ketchum