Is there anything special about how the Fortnite circle is rendered?

Zablorg

For those unfamiliar, the circle shrinks over the course of a Fortnite match to restrict the circle of play. You can see it as the blue wall in the promo image below.



I'm uncertain how they go about rendering this effect, for two reasons: for a circle shape, the curvature seems very smooth (but it could be that they're just dedicating a lot of polygons). Furthermore, you could be very close to one end of the circle and be extremely far away from any other given point. You'd almost want to mix LODs at that point- could it be using several meshes, each representing a segment of the circle, so that it can mix LODs between them based on distance?

I'm pretty curious as to whether there's any way to make this circle effect in UE4 without the use of a mesh?

Obscura

Its very straight forward in my imagination... Even if its a cylinder with 1000 segments, it would be only 2k triangles which can nicely live without any lod, and the curvature would be smooth as well. When the circle gets smaller, it could be swapped to a lower poly one to reduce overdraw in the far.