I came across this fantastic game a couple weeks ago and since then, I'm trying to figure out how are they doing this paint effect in real time. Would be great if somebody could break it down for fellow developers like myself. Here are few approaches that I have in mind but none of these seem to be the ideal case here. 1: The levels are made of modular meshes and for every mesh there is a second mesh underneath it, for every mesh in upper layer, there's a grayscale material applied to it while the meshes in lower layer, has the colored materials. With OnCollisionEnter, they are dissolving the upper mesh and revealing the lower colored geometry and creating an illusion of paint effect there. 2: Using some sort of particle system as shown in the video below, can it be? idk. Please let me know if I'm right or guide me if I'm not.