Fake fog vol­ume in Unre­al Engine

Very easy way to imple­ment a fake fog vol­ume to use in your Unre­al Engine 4 projects.

This easy to do tuto­r­i­al will let you cre­ate a fake fog to use in your Unre­al Engine project. But with the ease of cre­ation come a few cons: there are no sides to the fake vol­ume, and it does­n’t look that great if look­ing from inside the volume.

Fake Fog Material

First of all, let’s cre­ate the mate­r­i­al and call it M_FakeFog. Don’t for­get to change the Blend Mode to Transculent.

Let me explain some of the nodes:

  • Col­or and Emis­sive Col­or are both Vec­tor Parameters
  • Emis­siveStrength, DepthOpac­i­ty and Depth­FadeDis­tance are all para­me­ters. You can see their default val­ues in brack­ets besides “Param” word.
  • 0 that goes into the “Alpha” input of the Lerp node is a constant.

That’s it. Save your new mate­r­i­al and cre­ate an instance of it, so you can tweak the para­me­ters on the fly.

Fake Fog Blueprint

Now cre­ate a blue­print Actor (I called mine BP_FakeFog, duh).

  • Add an Instanced­Sta­t­icMesh component. 
  • Choose a sta­t­ic mesh to use as a fog lay­er (you can go pret­ty wild here, but I used one of the default planes that comes with the engine). You will need to assign it in the cor­re­spond­ing field in the Instanced­Sta­t­icMesh com­po­nent. Assign the mate­r­i­al instance you cre­at­ed ear­li­er here as well.
  • Add two new vari­ables — Num­berOfIn­stances and SpawnDis­tance, both of them are ints. Set the default val­ues to 5, for example.

Now, in con­struc­tion script, do the following: 

We’re basi­cal­ly adding sev­er­al planes on top of each oth­er progressively

Now put the bueprint some­where on the lev­el, play around with the para­me­ters — do as you please! 

Cre­ate a tox­ic pool of glow­ing acid? Easy. Just a few tweaks to the mate­r­i­al instance.