To aid with what I'm trying to achieve, please think of a supermarket shelf filled with a number of a product. When a customer purchases, one of these products disappears off the shelf. When the player re-stocks the shelf, the product reappears.
My initial thinking was that I could just spawn individual static meshes for each product but this would mean thousands of meshes to be spawned and displayed so my thoughts went to a single mesh of the all of that product on the shelf and a material with an opacity mask that changes as needed. Somewhere in the back of my head, I think this can be done with a bit mask but I can't find the right resources to get me started with this.
If anyone has any other ideas, they'd be welcome and pointing me in the right direction of the opacity mask idea would be greatly appreciated.