Help with the logic: Graffiti System

Hi there !, im trying to make a graffiti system, and i have a question about decals.

First, here’s what i made (Unreal Engine 4 Graffiti Blueprint System - YouTube). The decal spawn with alpha 0%. My question is, Can i “shoot” in specific area and set the decal to alpha 100% (in an area where i shoot) ?
And if i use this (if it possible?) how can i checke the graffiti is completed ?.
Someone throw this idea, if i make a virtual grid maybe this can checke if the graffiti is 80% completed or 100%.

Here’s an example :

Or this is more simple, let me know please. Thanks

Hey Naks312!

Not tested but maybe try adding some sort of collision bounds when you start painting so you can have some sort of ratio to work with. Then, using the point you’ve painted on, start adding decals that are masked with a paint shape and at the vector parameter’s position on the UV’s. Then have the texture of the graffiti, and used Screen Aligned UV’s to make them match up seamlessly.

Hope this helps!

are the decals viable to this system ? i know if i have a lot of decals this gonna be deleted.