At this point, we have the geometry, or basic shape of our crate down, but it still doesn't really look like the objects we see in other games. The reason is textures. Texturing our object will create all those little details that will make our game asset worthy of the level we have built. Making our textures and getting them on the object is a two-step process. First, we need to tell our textures how to behave and that takes a UV map:

Learning unwrapping with a basic cube

A UV map is a set of coordinates that tell texture maps we have placed on a game asset how to wrap themselves around our object. The principle is to take your 3D object and flatten it, so that we can apply an image to the outside in a manner that doesn't tear or stretch the texture. This allows us to create detailed texture maps that apply things like scraped edges, rust spots, paint colors, visual screens, and more. Without it, Unreal will not know how to texture our object in...