Can I have environmental fog evaluate after post process? (Or alternative)

Hi there. So I’m mostly a noob with materials in ue4 and I have a post process that creates an outline around all objects on the scene. I don’t know what magic makes it work but it does. That’s great. However, I’ve also placed an exponential height fog which looks amazing except it does not obscure the outline. Betrayal… Presumably, this is because the post process is evaluated afterwards (hence post, I’m guessing). So I’m looking for a way to have the fog affect the outlines. I was thinking that if the fog was also a post process material I can evaluate it at the end, thus solving my problem. Yay! So I’ve been looking around for tutorials or free assets to accomplish this. So far, I’ve found a post process material that seems to create fog. Except it’s not working and my material kung fu is not strong enough to know what it’s doing or why it doesn’t seem to be working for me. I would love to ask people here for any help creating this post process fog, and if anyone knows of a good in depth resource for a terrible beginner on learning and becoming advanced on ue4 materials, that would be killer. But any help is welcome.

For what it’s worth, I have a background in 3D animation software (Maya and C4dD). Here’s a picture of the post process fog material I found.


Only way I could see that happening is by taking data from the Depth Buffer and using that to recalculate the fog to then basically just re-apply the fog in your post-processing material.
Kinda a waste though. Means you’re rendering fog twice an it’s unnecessarily complicated. Not sure if there’s an alternative though. Maybe look around and see if there’s something like a FogAtPixel node or something?

Still looking for an answer to this myself. If you are doing some toon based post process effect but still want fog, bloom, god rays, etc. Then it has to be applied or reapplied after the post process effect. Any update on this?

“Post Process” does what it says, it’s applyied after everything.

You could manually call calculate fog function from post process.