So i'm looking to great an infestation element for my topdown 2D game, where an "spore" gameobject spreads infestation around itself. The idea being that left unchecked this would end up covering the entire ground of the map. I want to avoid using tiles for this, so i though about creating a dynamic mesh which i could grow in size/shape that would sit just above the tilemap so it would draw ontop of it (I'm using the tilemap only for visuals) I don't know a huge amount about creating and manipulating a grid from code, i've seen very basic examples online. But my issue is that i would want this mesh to abide by terrain, such as either not going over cliffs, or being slower to spread over cliffs. First of all, is this something that is possible, or at least not extreamly difficult to do? If so could anyone give and suggestions on how to go about something like this?