Top-Down Fog of War in Unreal Engine: Complete Guide

Top-down fog of war, the lit circle that follows your hero through a darkened level while cliffs and walls block what they can see, looks like it needs expensive GPU visibility work. It does not. The whole effect is a screen-space post-process material driven by a handful of parameters, plus a small Niagara system for beacons. No compute shaders, no per-unit ray casts for the visuals.

How the system fits together

One actor and one material do the work. An unbound post-process volume darkens the whole level through the M_Main_Fog_Volume material. A Fog Manager actor feeds that material live data every frame and the material assembles a single black-and-white mask, white where the player can currently see, and lerps the scene between dark and lit:

EmissiveColor = lerp(SceneColor * Darkness, SceneColor, mask);

Everything else in this guide is about producing that one mask: where the player is, where the beacons are, and what cliffs block. Each step below builds one piece of it.

What you need

This is intermediate Unreal Engine: you should be comfortable reading a material graph, writing a little C++, and working with render targets. It targets UE5 and has no third-party dependencies. If you would rather skip the build and drop it in, the Multiplayer Fog of War plugin packages the whole system, replicated and performance-minded, for top-down games.

The build, step by step

Work through the seven steps in order for the complete system, or jump straight to whichever piece you need.