I’m glad to introduce you Outliner — the post process material to outline and fill objects in Unreal Engine 4.
Outliner has 7 presets (CustomDepth Stencils) in material instance. You can add more manually, if you need to. For each preset you can change the way it outlines and fills objects. Each preset can be used in different situations (i.e. highlight hostile objects with red outline using preset 1 and friendly objects using preset 2). Each preset have separate options for outline and fill.
[li]Enable outline or fill (or enable both).
[/li][li]Change visibility option:
[li]Outline or fill is always visible, even if the object is not (i.e. you can see the effect through walls and other objects).
[/li][li]Outline or fill affect only the part of object, that is behind other object.
[/li][li][*]Outline or fill affect only the part of object, that is visible.
[/li][li]Change outline thickness.
Since you have separate options for outline and fill, Outliner can, for example, outline the part of object which is visible in red, and fill the part of object which is hidden in green.