Raytraced AO to create dirt effect?

Is there a way to access he raytraced AO to create a dirt effects? Similar to this video below with pre-computed AO.

[Nick Reynolds: Unreal 4 Baked AO Dirt Mask - YouTube

T](Nick Reynolds: Unreal 4 Baked AO Dirt Mask - YouTube)

You could probably do something with a world-aligned mask multiplied against the AO pass in a Post-Process material.

Think I got something started with Material Expression "SceneTexture node but it errors give back an error when i try to blend it with normal texture or use a an alpha in a lerp node. Still need to look up how to blend the post-process material and or texture i guess with a normal material…Thanks for the insight!

Raytracing isn’t developed enough to work on things like this

Yeah, I realized that. I was able to use the mesh distance field technique but when I switch to dx-12 version it bugged out and rendered my textures white.