In this game I'm making, I want my players to be able to remove rust from an object based on collisions from another object such as a wire brush. Since it's a VR game, performance is key.
I've been having a hard time getting on the right track; I think I'm not asking the right questions. The closest I've gotten was a video about making a scratch-off lotto ticket. Someone in the comments to that video says:
Good Idea. But, this isn't practical for any real world apps. It instantiates too many gameobjects. There are better more efficient ways of achieving this effect using shaders or render texture.
They don't really expand on that further, but I did do a little more searching to see how I might do this using shaders. I found this video about using replacement shaders, but I'm still not sure if that's the right track. I don't know If something like that is the smartest way to do it.
I'm basically a complete noob when it comes to shaders and textures so this is new territory for me. I apologize if this is a duplicate question, I've tried searching but haven't found anything quite like what I'm looking for. Please let me know if there's anything I can explain further, and any help that gets me pointed in the right direction would be greatly appreciated.