Dark Corruption VFX, Use a mesh collision to control vertex paint?

Hello all, I was hoping to ask someone a bit more knowledgeable about a VFX thing ive been thinking about. the idea: player walks along as the environment around them changes from a dark texture to a light texture. the effect will be within a range of the player, and will create a wake behind them, which ideally slowly expands outwards.

2 ideas:

The player has an invisible sphere around them that actively paints the vertex weights (is this possible?) so I could lerp the vertex weights to different textures.

The player drops spheres behind them, which slowly expand and paint the areas they come in contact with (sphere masks? or distance fields?)

Decals wont work for this effect, to my knowledge.

Requirements: Cleansed area is a lasting effect (or goes back to dark after the player has gone away for a long time) the path behind the player will be cleansed, ideally following the player path.

if anyone can offer any ideas or documentation or anything that could help me. that would be great.

EDIT: I realized you want it to linger like a trail. You’ll have to dive into render targets and stuff along those lines. You’d end up making an alpha map that gets updated every tick and controls the overall blending between the two materials. You’d also have to have some kind of sphere actors, that will expand/contract, for filling the alpha map.

I spent some time messing around with different methods of pulling this off because I actually need a similar effect in my game. This really early version uses only deferred decals(they have a world aligned texture/normal in them). I still want to add in a lot more functionality, but it’s the basic gist of it. I need to practice with render targets and find a way to pull this off using them, but this works for now.

So is this kind of along the lines of what you’re looking for?:

This looks interesting, I cant zoom in on any of the images you have posted, I literally just watched the render targets stream from unreal. Looks like it could work, though it would need to apply to multiple meshes. and im unsure how costly to the scene it will be! I think dropping spheres behind the player is the way to go as you say!

Thanks for the reply!

That is a really cool effect! I completely forgot about world aligned textures in relation to decals! I think this would work, for the opposite effect. As the decals are still temporary to the scene. and would eventually need to completely fade away. I imagine my effect to slowly expand and remove the corruption from an area pertinently. It is going to be a challenge to try pull off. If its even possible. If not, this might be the way to go!